(vi)
3x
2
-
5y
3
=
-2
;
x
3
+
y
2
=
13
6
Soln.
3x
2
-
5y
3
=
-2
9x
…(i)
Substituting eqn (iii) in eqn (ii)
∴
2
-12+10y
9
+3y
=
13
∴
-24+
9
+3y
=
13
∴
-24 + 20y
=
117
∴
47y
=
141
∴
y
=
3
Substituting y = 3 in eqn (iii)
x =
-12 + 10
9
x =
-12 + 30
9
x =
18
9
x =
∴
2
Solution is x = 2, y = 3
-10y
+ 27y
∴
20y
=
117
+ 27y
+ 24
2
Solve the denominator
There are two denominator
3 & 2
Their L.C.M = 6
=
-12
6
6
×
6
x
3
+
y
2
=
6
6
×
6
3x
2
-
5y
3
=
-2
13
6
Multiplying throughout by 6 we get
Similarly
3
2
2
3
2x
…(ii)
+ 3y
=
13
x
3
+
y
2
=
13
6
Multiplying throughout by 6 we get
Write the eqn
either X = something
Or
Y = something
9x
-10y
=
-12
9x
= -12
+
10y
x =
-12
+
10y
9
…(iii)
Either eqn (i) eqn (ii) or (iii)
(3)
How to get the value of x?
Substituting the value of y in (iii)
We have to substitute y = 3
20y
Consider one of the two equations
Let us Consider equation no. (i)
Consider (i)
Which equation is to be considered
You can consider either of the two equations
It is better to consider simpler of the two equations
First let us number the equation
Number the equation as (iii)
What is the name of the method ?
SUBSTITUTION Method
So we need to substitute something
substitute what ?
Substitute eqn. (iii)
Where ?
In the equation which was not considered
If any number is in the
denominator become than
it difficult to solve