On four exams, wallace’s grades were 79,93,91, and 68. what grade must he obtain on his fifth exam to have an 80 average?

(79 + 93 + 91 + 68 + x) / 5 = 80

Simplify

(331 + x)/5 = 80

Multiply 5 to both sides to isolate the x.

331 + x = 400

Isolate the x. Subtract 331 from both sides

x + 331 (-331) = 400 (-331)

x = 69

69 is your answer

hope this helps

pay attention in your classes and concentrate the best thing you can do to raise your test scores is to pay attention when you're supposed to be learning the material: in class!

take good notes.

do your homework.

use mnemonics and other tricks.

do practice tests.

note: the best i know.

where are the choices?