SOLUTION: justin earns scores of 75,83,77,and 81 on his first four exams in math class. the final exam is worth twice a regular exam(twice the weight). he wants to earn a B, so he needs at l
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Question 165667: justin earns scores of 75,83,77,and 81 on his first four exams in math class. the final exam is worth twice a regular exam(twice the weight). he wants to earn a B, so he needs at least an 80 average. solve the following equation to find the lowest score he can earn and still get his B!
(75+83+77+81+2x) /6 =80
I must show my work and i don't know how ???? please help me !!!!!
Found 2 solutions by jim_thompson5910, stanbon:
Answer by jim_thompson5910(35256) (Show Source): You can put this solution on YOUR website!
Start with the given equation
Combine like terms.
Multiply both sides by 6
Multiply
Subtract from both sides.
Combine like terms on the right side.
Divide both sides by to isolate .
Reduce.
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Answer:
So the answer is which means that he must an 82 or better to get an average of 80 or better.
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
(75+83+77+81+2x) /6 >=80
Multiply both sides by 6 to get:
316 + 2x >= 480
2x >= 164
x >= 82
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Chers,
Stan H.
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