X-number
8x-20=15+x (subtract x)
7x-20=15 (then add 20)
7x=35 (then divide by 7)
I think you've got it from now, if not, just do 35 divided by 7. But go over the steps, so that you know how to do these types of questions.
Uppose the fence was 350 ft from home plateAt what height was each ball when it
over the ?
