SOLUTION: Each student is given 20 problems. Five points are awarded for each correct answer, and two points are deducted for each incorrect answer. Ellen's score was 72. How many correct an

Algebra ->  Expressions-with-variables -> SOLUTION: Each student is given 20 problems. Five points are awarded for each correct answer, and two points are deducted for each incorrect answer. Ellen's score was 72. How many correct an      Log On


   



Question 95563: Each student is given 20 problems. Five points are awarded for each correct answer, and two points are deducted for each incorrect answer. Ellen's score was 72. How many correct answers did she have?
Is this the correct way:
20(5x-2y)=72

Answer by checkley71(8403) About Me  (Show Source):
You can put this solution on YOUR website!
NO!
5X-2(20-X)=72
5X-40+2X=72
7X=72+40
7X=112
X=112/7
X=16 CORRECT ANSWERS.
20-16=4 INCORRECT ANSWERS.
PROOF
16*5-4*2=72
80-8=72
72=72.