(a) y = 4x - 8

You find y-intercepts where x=0. Points look like (0,yInt).

Plugging in:

(yInt) = 4(0) - 8

Solves yInt = -8.

Y-intercept is the point (0, -8).

You find x-intercepts where y=0. Points look like (xInt, 0).

Plugging in:

(0) = 4(xInt) - 8

so 4(xInt) - 8 = 0

so 4(xInt) = 8

so xInt = 8/4 = 2

Solves xInt = 2.

X-intercept is the point (2, 0).

Part (b) is done the same way.