Question

Jackie scored 81 and 87 on her first two quizzes . Write and solve a compound inequality to find the possible values for a third quiz score that would give her an average between 80 and 85, inclusive.

Answer 1

80 ≤ [(81 + 87 + x) / 3] ≤ 85

multiplying by 3 ... 240 ≤ (168 + x) ≤ 255

subtracting 168 ... 72 ≤ x ≤ 87

Answer 2

Thank you!