Luis had $263.45 in savings. he spent $207.48 on computer equipment. how much does he have left in savings?

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

The perimeter of a movie screen is 54 meters. the screen is 18 meters wide. how tall is it?

Complex numbers multiply √-4 * √-25 and show all intermediate steps. alternative notation is sqrt(-4) * sqrt(-25).