4x + 3y = -13
y = 6x - 8
Substitute the value of y in the first equation,
4 x + 3 ( 6 x - 8 ) = -13
4 x + 18 x -24 = -13
22 x = 24 - 13
22 x = 11
x = 11/22 = 1/2
plug the value of x in y = 6x - 8 and find y
y = 6 ( 1/2 ) - 8
= 3 - 8 = - 5
check these values in both equations,
4x + 3y =? -13
4(1/2) + 3 ( - 5 ) = 2 - 15 = -13
for the second equation
y = 6x - 8
y - 6x =? -8
-5 - 6 ( 1/2) = -5 - 3 = -8