SOLUTION: Use an algebraic approach to solve the problem. (Objective 2) Aura took three biology exams and has an average score of 85. Her second exam score was 5 points better than her fi

Algebra ->  Equations -> SOLUTION: Use an algebraic approach to solve the problem. (Objective 2) Aura took three biology exams and has an average score of 85. Her second exam score was 5 points better than her fi      Log On


   

Question 885897: Use an algebraic approach to solve the problem. (Objective 2)
Aura took three biology exams and has an average score of 85. Her second exam score was 5 points better than her first, and her third exam score was 5 points better than her second exam. What were her three exam scores?
(lowest score)

(highest score)
Answer by josgarithmetic(39618) About Me  (Show Source):
You can put this solution on YOUR website!
The first, second and third scores, x, y, z, respectively.

%28x%2By%2Bz%29%2F3=85.

Her second exam score was 5 points better than her first, and her third exam score was 5 points better than her second exam.
y=x%2B5 and z=y%2B5.

A few different ways to go.

The last two equations: x=y-5 and z=y%2B5; substitute into the average85 equation:
%28%28y-5%29%2By%2B%28y%2B5%29%29%2F3=85
%28y-5%2By%2By%2B5%29%2F3=85
%283y%29%2F3=85
highlight%28y=85%29----ONE of the scores, the second score.
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highlight%28x=80%29 and highlight%28z=90%29.