Hello! The x-intercept is where the line crosses the x-axis when y = 0. We already have the expression shown. We will plug in 0 as y to get this:
5x - 8(0) = 40.
As you probably know, anything times 0 is 0, so -8 * 0 is 0. All we have is 5x = 40. Divide each side by 5 to isolate the x. 5x/5 cancels out. 40/5 is 8. There. x = 8. The x-intercept is (8, 0).