Answers:
The expression is 12n
He reads 84 books in 7 months
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Step-by-step explanation:
For 1 month, he has read 12*1 = 12 books
For 2 months, he has read 12*2 = 24 books
For 3 months, he has read 12*3 = 36 books
and so on
If we let n represent the number of months, then 12*n or 12n represents the number of books read after n months. The variable n is some placeholder for a positive whole number.
If we replaced n with say n = 7, then 12*n = 12*7 = 84 books are read in 7 months.