-24 - 8x = 12y
Divide by 12
y = -2/3x - 2
1 + 5/9y = -7/18x
Subtract 1
5/9y = -7/18 - 1
Divide by 5/9, or multiply by 9/5
y = -7/10x - 9/5
Find the x-value they intersect at...
-2/3x - 2 = 7/10x - 9/5
Add 2
-2/3x = 7/10x + 1/5
Subtract 7/10x
(-20/30x - 21/30x) = 1/5
-41/30x = 1/5
Divide -41/30
x = -6/41