A branch of mathematics that uses variables is algebra
Answer:
$10
Step-by-step explanation:
The hardcover books are $12 each which would be $60 out of the $100. There are four more paperbacks meaning they would be $10 each and cost $40 total.
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Answer:
9
Step-by-step explanation:
5(n-2)=35
5n-10=35
5n=35+10
5n=45
n=45/5
n=9
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