Math
posted by Jazmin .
Jeremy got scores of 93,82,91, and 88 on his first four math test. What score must he get on the fifth test to have an average test grade of 90 for the five test ?
Can someone explain step by step. Please

For average grade of 90, must all add up to the average times the amount of tests.
So, 90*5 = 450
x+ 93+ 82+91+88 = 450
x+(82+88) + (91+93) = 450
x + (170 + 184) = 450
x+ 354 = 450
x+4 + (350) = 450
x+4 = 100
x = 96 
Thank you so much this is better than the way my teacher explained. :)

Sariqs last four test scores in history were 87,85,91,and 88. What scores on his next test will give him an average of 90 or above? Write and solve an inequality.