SOLUTION: Christian D'Angelo has scores of 68, 65,75, and 78 on his algebra tests. Use a compound inequality to find the scores he can make on his final exam to received a C in the course. T

Algebra ->  Inequalities -> SOLUTION: Christian D'Angelo has scores of 68, 65,75, and 78 on his algebra tests. Use a compound inequality to find the scores he can make on his final exam to received a C in the course. T      Log On


   

Question 205272: Christian D'Angelo has scores of 68, 65,75, and 78 on his algebra tests. Use a compound inequality to find the scores he can make on his final exam to received a C in the course. The final exam counts as two tests and a C is received if the final course average is from 70 to 79.
Answer by alicealc(293) About Me  (Show Source):
You can put this solution on YOUR website!
Final exam score = x

average score = %2868%2B65%2B75%2B78%2B2x%29%2F6
= %28286%2B2x%29%2F6
70 ≤ average score ≤ 79
70%3C=%28286%2B2x%29%2F6%3C=79
70%2A6%3C=%28286%2B2x%29%3C=79%2A6
420%3C=%28286%2B2x%29%3C=474
%28420-286%29%3C=2x%3C=%28474-286%29
%28420-286%29%3C=2x%3C=%28474-286%29
134%3C=2x%3C=188
divide them by 2:
67%3C=x%3C=94