Jerry had an average score of 85 on his first eight quizzes. He had an average

[Mary Margaret]

score of 81 on his first nine q? Explain without using algebra. You can type the mathematical process, but also explain it in words.

 

[Emily]

u can't explain it without using algebra.

85+85+85+85+85+85+85+85+x
-----------------------------------------------
9

Thats over 9.

= 81

so...
(680 + x)/ 9 = 81

so x = 49