Question

PLEASE HELP ME WITH THIS PROBLEM IVE BEEN ON IT FOR 3 DAYS NOW!

Lucy wants to be exempt from her semester exam. In order for that to happen, she has to average an 85 over 3 test grades. Her first 2 test grades were 81 and 86. What does Lucy need to make on her third test in order to have an exact average of 85 and be exempt from her exam?

Answer 1

She needs to get 88

Explanation:

make an equation to find the unknown answer:

`(81+86+x)/(3)= 85`

to find x

81+86+x=85·3

x=85·3-86-81

x=255-86-81

x=88