Question

An integer is 3 less than 5 times another. if the product of the two integers is 36 what are the integers?

Answer 1

• 12
• 3

Explanation:

You want two integers with a product of 36 such that one is 3 less than 5 times the other.

Setup

Let x be "the other" integer. Then one is (5x-3), and the product is ...

x(5x -3) = 36

Solution

5x² -3x = 36 . . . . . . eliminate parentheses

x² -0.6x = 7.2 . . . . . . . divide by 5

x -0.6x +0.09 = 7.29 . . . . . add (0.6/2)² to complete the square

(x -0.3)² = 7.29

x = 0.3 +√7.29 = 0.3 +2.7 = 3

5x -3 = 5·3 -3 = 12

The two integers are 12 and 3.