Mallory had an average of 87 on her first three algebra quizzes. She made the same score on the first two quizzes and 9 points higher on the third quiz. What was her grade on each quiz?

Answer 1

mean = sum of scores/number of scores
Let x = score on first two quizzes
87 = (2x + x+9)/3

Solve for x, then x+9.

Answer 2

It worked, thanks!

Answer 3

You are welcome.