The difference of a number and seven is twelve idk what to do it telling us to turn it in to an equation

Aline parallel to a triangle's side splits ab into lengths of x - 5 and x + 2. the other side, ac, is split into lengths of x and x + 12. what is the length of ac? a) 12 b) 24 c) 36 d)

Rose bought a new hat when she was on vacation. the following formula describes the percent sales tax rose paid b=t-c/c

Anyone know these questions? i need ,.