Question

2x+3y=12:;3x+4y=15 by substitution method ​

Answer 1

2x+3y=12

2x=12-3y

x=(12-3y)/2 ....... (1)

3x+4y=15

3(12-3y)/2+4y=15

18-(9y/2)+4y=15

-y/2=-3

y=6

substitute value of y in first equation

2x+3(6)=12

x=-3

(x,y)=(-3,6)

hope it is useful for

Answer 2

Answer:

2x + 3y = 12. .....(1) × 3

3x + 4y = 15 .......(2) × 2

6x + 9y = 36

6x + 8y = 30

- - -

----------------------

y = 6

putting then value of y in eqn 1

get x = -3