How do you solve 8x-9y=32.5 and 7y-2x=-10.5 using substitution?

1 Answer
Sep 9, 2017

Solution: x= 3.5 ,y = -0.5

Explanation:

8x-9y= 32.5(1) , 7y-2x= -10.5(2) , From equation (2)

we get 2x= 7y+10.5 or x= 3.5y + 5.25 (3), Putting

x= 3.5y + 5.25 in equation (1) we get,

8( 3.5y + 5.25) -9y = 32.5 or 28y+42-9y=32.5 or

19y = 32.5-42 or 19 y= -9.5 or y = -0.5 Putting

y = -0.5 in equation (3) we get, x= 3.5 *(-0.5)+5.25 or

x=3.5 :. Solution: x= 3.5 ,y = -0.5 [Ans]