Factorisation - Which method to use? (Responses)
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Q1. Choose the most appropriate/ effective method to factorise the following:Q2. Choose the most appropriate/ effective method to factorise the following:Q3. Choose the most appropriate/ effective method to factorise the following:Q4. Choose the most appropriate/ effective method to factorise the following:Q5. Choose the most appropriate/ effective method to factorise the following:ScoreNameReg no.GroupDescribe how would you decide which method to use to factorise the algebraic expression.Remarks/ Feedback
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By identifying the common factorBy groupingBy special productBy special productBy cross method5 / 5Christabel Lee11When the expression includes factors that are common, we factorise it by identifying common factors.
When the expression is (A+B)^2, (A-B)^2 or (A+B)(A-B), special product is used.
Cross method is used when there are a quadratic expression.
Grouping is used when there are terms that have the same variable.
Clear explanation for the first three methods.
This can be improved by saying #1 is the overarching step - regardless of the form of the alegbraic expression given.

For grouping, this is usually applied when the expression has 4 or more terms, and the number of terms available is even.
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By identifying the common factorBy groupingBy special productBy special productBy cross method5 / 5Annie41Check how many terms are being used.This is just the first step, what's next? Need to elaborate based on the various scenarios that we have learnt.
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By identifying the common factorBy groupingBy special productBy special productBy cross method5 / 5Ethan Loke131For common factors, I need to see if the coefficients or the variables are common.
For grouping, there must be an even number of terms and must have both terms that have the same variable or coefficient per 2.
For special products, I need to see that it is a^2 - b^2.
For Cross Method, it must be a quadratic expression like a^2 + a + 2.
Clear explanation with an attempt to illustrate with examples.
For common factors, note that it's the 'coefficient to the variables' and the 'constant' term (which is not mentioned).
For grouping - what's this "per 2"?
For special product, just need to bear in mind that we are choose to work with a^2 - b^2 as this is the most straight forward one. The other 2 special products can be done through "cross method"
For Cross method, the generic expression is Ax^2 + Bx + C where A, B and C are real numbers.
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By identifying the common factorBy groupingBy special productThis expression cannot be factorised!By cross method4 / 5loke yi ming141when there is a power, an algebraic expression with the same algebraic expression and a constant in the equation, use cross method. when there is subtraction between the two numbers/algebraic expression in the equation, use special product. when there is a common factor across all of the numbers/algebraic expression, use common factors. all this methods can be used across the equation as there may be a case where a line needs another method.Apart from the segment that is highlighted in blue, you need to be clearer in your explanation. For example, you could provide an example when you described the expression that you can apply special product method. Do not rely text for the entire explanation. Include examples to add clarity.
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By identifying the common factorBy groupingBy cross methodBy special productBy cross method5 / 5Lucas151Look at the number of terms. (If it is a quadratic expression, I would use cross method)What you've described is very limited - if it is quadratic expression, are there other possible means to factorise?
What happens if it's not a quadratic expression, what would you suggest to do?
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By identifying the common factorBy groupingBy cross methodBy special productBy cross method5 / 5George Ma161If there is a a similar common factor in the numeral sentence, means that you must use the identifying common factor so that they are able to be easily calculated by finding the common factor and if the factors of a number is able to make up the second last number, means it is necessary to use cross method and for grouping, there will be something similar in the number sentence such that the similar numbers will be calculated together so it will be grouped and that the number sentence will be able to be calculated.You have combined everything in a single sentence and as a result it looked confusing. The blue segment is the clearest.
Try to start each method with a new paragraph. Provide examples to add clarity.
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By identifying the common factorBy groupingBy special productBy special productBy cross method5 / 5Sara Woo62By looking at the question. If there is one common factor with something squared, the method used is most likely cross method. If the expression is A^2-B^2, use the special product. If there are 4 terms, it is most likely grouping. If there is a common factor in all the terms, the method to use is to identify the common factors.Can drop the first sentence (green).
Need to add more clarity to the blue segment. Unable quite figure out the expression you are describing. Insert an example to add clarity to what you try to describe.

The remaining part (in black) are clear.
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By identifying the common factorBy groupingBy special productBy special productBy cross method5 / 5Ho Rui Yang102When the numbers can be squared, I used special product. When the numbers seem that they cannot be factorise, but the highest power is two, I use cross method. When the numbers can be easily factorise, I identify the common factor. If there are 4 terms very likely it is groupingA good attempt to explain but there is a need to improve the clarity, to add some examples so that we can associate the 'pattern' to look out for so as to decide which method to apply.
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By identifying the common factorBy identifying the common factorBy cross methodBy identifying the common factorBy cross method3 / 5Mohamad Zuhairi Bin Zainudin172When I look at the expression, I think about the ways of how to work them out in my head.You have not answered to the question. Need to elaborate your thought process.
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By groupingBy groupingBy special productBy cross methodBy cross method4 / 5Muhammad Adam182For grouping and identification of common factors, you must only use 4 or 6 terms. For special product or cross method, you mostly use 3 terms.Are you combining two methods in the first sentence? The explanation has to be separated as one builds on another.
For the last sentence, there is not enough info to help us decide which method to use. Need to elaborate.
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By identifying the common factorBy groupingBy special productBy special productBy cross method5 / 5Norman Hamdan202It depends on the question. If the question consists of a varible squared, a variable and a number, usually we use cross method. If it consists of an even number terms with 2 common factors, we usually use the grouping method. If it consists of a term squared minus a term squared, we usually use factorise by special products. When there are common factors, we factorise the terms by identifying the common factors.Omit the green text.

Explanation is very clear. It would be even better if it's supported with some illustrations.
On another note, it would be more encompassing if you move the last method (identifying common factors) to the very first step as it applies to all expressions.
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By identifying the common factorBy groupingBy special productBy groupingBy cross method4 / 5Qin Guan212By looking at how the question is like You have not answered to the question. Need to elaborate your thought process.
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By identifying the common factorBy groupingBy special productThis expression cannot be factorised!By cross method4 / 5Richard Kok Zen Xian222I would first look at the question. Then, I would start identifying the common factors. If there is no common factor or after using factorising using common factors but is still not factorised completely, I would proceed to the cross method. If I see that the terms can be grouped together, I will try using grouping. If any part of the question has something like - (A+B)^2, (A - B)^2 OR (A + B)(A - B), then I will try using special products.Text in green can be omitted.
You are right that no matter what is given, always look for common factor first.

The remaining explanation is pretty clear. It's a good attempt to give some illustrations.
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By identifying the common factorBy groupingBy cross methodBy special productBy identifying the common factor4 / 5Foo Lin Hui23Examine the question and see how the numbers and algebraic expressions are arranged You have not answered to the question. Need to elaborate your thought process.
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By identifying the common factorBy groupingBy special productThis expression cannot be factorised!By cross method4 / 5Sofia Pineda33It would depend on the numeric values and if they have a common factor.You have not answered to the question. Need to elaborate your thought process.
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By groupingThis expression cannot be factorised!By cross methodBy groupingBy cross method2 / 5Simran53I just look at the question and remember the examples for each method to factorise and use the most efficient method.
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By identifying the common factorBy groupingBy special productBy identifying the common factorBy grouping3 / 5Hafiz Sadali93Checking the algebraic expression and the numbers and check if it can be factorised by the following methods.You have not answered to the question. Need to elaborate your thought process.
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By groupingThis expression cannot be factorised!By special productBy identifying the common factorBy cross method2 / 5Hakimi193I would check whether the method can be used to factorise the expression.You have not answered to the question. Need to elaborate your thought process.
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By identifying the common factorBy groupingBy special productBy special productBy cross method5 / 5Wan Hanafi243Grouping can be used if there are 4 terms.
Special product can be used if the question abides by A^2 - B^2
Identifying Common Factors can be used if the terms in the questions have a common factor.
For grouping - Note that usually we are given 4 terms. There are occasions you are given more terms (as long as they are even terms, there's a chance for this method).

You have missed out the CROSS method?
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By groupingBy cross methodBy groupingThis expression cannot be factorised!This expression cannot be factorised!0 / 5Hao Min74The way the question is structured. Example if the question has same factors, we can use 'Identifying common factors', but if You have only described one method clearly. How about other methods?
On another note, it seemed like you have not applied what you described when answering Q1.
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By identifying the common factorBy groupingBy special productThis expression cannot be factorised!By cross method4 / 5Corwin Chong Yao Kiat84I look for groupings and common factorsWhat do you do after this?
are the scenarios so limited? Think again.
You need to elaborate your thought processes
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By identifying the common factorBy groupingBy special productBy special productBy cross method5 / 5Jia Zeyu114Identify the amount of terms and determine the method to use.You have not answered to the question. Need to elaborate your thought process.
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By groupingBy identifying the common factorBy special productThis expression cannot be factorised!By identifying the common factor1 / 5Joel Chew124Examine the questionYou have not answered to the question. Need to elaborate your thought process.
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By identifying the common factorBy cross methodBy special productBy special productBy identifying the common factor3 / 5Matthew Tan234See how the question is phrased.You have not answered to the question. Need to elaborate your thought process.
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By identifying the common factorBy groupingBy special productBy special productBy cross method5 / 5Xee Zun Kye254Start with identifying common factors
Quadratic expression use cross method
?^2-?^2 use special products
Use grouping if there are many similar variables e.g. ab+ba-a+b
Yes. The first line applies to all cases.
For grouping, you need to give greater clarity, for instance, how many terms do we normally have in those expressions? (even no. of terms).
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