So in order to solve for x, you need to isolate it. You're first step is to distribute 1/8 to 8x and 15. You get 1x + 1 and 7/8=24. Now you to do the inverse operation of addition (because you're adding) and you subtract 1 7/8 from each side. So now you have the equation 1x+1 7/8-1 7/8=24-1 7/8. You finish subtracting. 1 7/8-1 7/8 cancels out, so you have 1x=23 3/8. Now you divide by 1, and get x=23 3/8.
You can set of an equation of 45 - x = 111 x representing the amount of miles Nicole drove. You would subtract 45 from both 45 and 111 and get that x = 66.
