4) a student score is 83 and 91 on her first two quizzes. write and solve a compound inequality to find possible values for a thord quiz score that would give anverage between 85 and 90.
a. 85≤83+91+n/3 ≤90; 81≤n≤96
b. 85≤83+91/2+n≤90; -2≤n≤3
c. 90≤83+91+n/3 ≤85; 96≤n≤81
d. 83≤85+91+n/3 ≤90; 73≤n≤94
i don't understand this question