To find the x-intercept, set y to 0.
a) This one has no x-intercept, y is always -5 so it never crosses the x axis (which is defined by y=0).
So the x intercept is (3,0) or just 3.
Same answer as b).
d) x is always equal to -4 regardless of y, so the x intercept is (-4,0).
Hope that helps.