Hi. I am having some problems with substitution method and i just can't seem to get these right. I have

Question

1. 2x - 3y = -1 with y = x-1
2. -4x + y = 6 with -5x- y = 21 and finally,
3. -5x + y =-3 with 3x -8y = 24

Answer 1

2 x - 3(x-1) = -1

2 x - 3 x + 3 = -1

-x = -4

x = 4
y = x-1 = 3
etc

check
8 - 9 = -1 right