Question

By using elimination method , the solutions of 3p –2 q = 0 and 2p – 3q = -10 are : *

Answer 1

Multiply first equation by 2 and the second equation by 3


Then subtract 2 from 1
6p-9q-6p+4q=-10-0
-5q=-10
Q=2

Answer 2

Answer :

p = 4 , q = 6

Solution :

Here ,

The given equations are ;

3p - 2q = 0 -----------(1)

2p - 3q = -10 ------------(2)

Now ,

Multiplying eq-(1) by 3 , we get ;

=> 3×(3p - 2q) = 3×0

=> 9p - 6q = 0 -----------(3)

Now ,

Multiplying eq-(2) by 2 , we get ;

=> 2×(2p - 3q) = 2×(-10)

=> 4p - 6q = -20 ----------(4)

Now ,

Subtracting eq-(4) from eq-(3) , we get ;

=> (9p - 6q) - (4p -6q) = 0 - (-20)

=> 9p - 6q - 4p + 6q = 20

=> 5p = 20

=> p = 20/5

=> p = 4

Now ,

Putting p = 4 in eq-(1) , we get ;

=> 3p - 2q = 0

=> 3×4 - 2q = 0

=> 12 - 2q = 0

=> 2q = 12

=> q = 12/2

=> q = 6

Hence ,

p = 4 , q = 6