Help ME plaese :D ::D TOT TOOOT

Every time you drive you will experience a combination of driving conditions and environments.

Naomi’s parents want to have 50,000, saved for her college education, if they invest 20000 today and earn 7% interest compound annually, about how long will it take them to save 50 thousand

What is the answer to this question? i'm a bit stumped. also how do i do it? 5(x - 4) = 2(x + 5)