9514 1404 393
Answer:
72 +13n = 163
7 nights
Explanation:
At 13 pages per night, Mario will read 13n pages in n nights. That plus the pages already read will total 163:
equation: 13n +72 = 163
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To solve this, we can subtract 72, then divide by the coefficient of n.
13n = 91 . . . . . . subtract 72 from both sides
n = 7 . . . . . . . . divide both sides by n
Mario read 7 nights.