Sara had 126 dollars to spend on 9 books. After buying them she had 18 dollars. How much did each book cost?

$12

Since we know she had $18 left over, we can just subtract $18 from $126 to get $108. and now we can just do 108/9 to get 12

15

step-by-step explanation:

we are given the following expression and we are to solve it and find the product:

-13 × (-5)

solving the given expression in the standard order of solving a mathematical expression, beginning with the opening of brackets and then multiplying the terms and changing their signs.

-3 × -5 = 15 (answer is positive because when negative is multiplied with negative, it gives a positive answer)