Question

Solve the following system using the substitution method.

x + 6y = –5
2x – 9y = –17

Answer 1

multiply first eq. by 2 both sides
2x + 12y = -10
now


2x + 12y = -10


2x – 9y = –17
_______________
- + +
0 + 21y = 7
=> y = 1/3

now put this value in any of the 2 eq. and solve for x

Answer 2

let x=-(5+6Y)...(1) the substitute in the equation 2x -9y=-17...(2) where it will become 2(-5-6y) -9y=-17 the solve for y after finding y subtitute y to equation 1.