First you would need to combine like terms. do you know how to do that?
6x + 2y = -88
2y = -88 -6x
y=-88/2 -6/2x
y= -44 - 3x
y = -3x - 44
Y intercept = -44
Slope/m = -3 (aka) -3/1
Let the time = x
Distance = Speed x time
One train is 75x, the other train 85x
Add together to equal total distance:
75x + 85x = 384
Simplify:
160x = 384
Divide both sides by 160:
x = 384 / 160
x = 2.4 hours