Question

Jonas collected data on the number of minutes he spent studying for each history test and his score on each test. He found that the linear equation y=1/5x+81 models his score after studying for x minutes. For how many minutes should he study if he wants to get a 90 on his next test? PLEASE HELP!!!

Answer 1

x = 45

Explanation:

y is the score on the test. To find the amount of time to study he needs to get a score of 90 on his next test, we need to find x ("y=1/5x+81 models his score after studying for x minutes.")

Initial equation

`y = (1)/(5)x + 81`

Replace y with 90

`90 = (1)/(5)x + 81`

Find for x

`90 - 81 = (1)/(5)x`

`9 = (1)/(5)x`

`5 * 9 = 5 * (1)/(5)x`

`45 = x`

Therefore, Jonas needs 45 minutes to get 90 on his next test.