Question

The square of the sum of a number
and five is eighty-one. Find the
number.

Answer 1

• The number is 4 or - 14

Explanation:

Let the number be x.

The we have equation:

• (x + 5)² = 81

Solve it for x:

• √(x + 5)² = √81
• x + 5 = ± 9
• x + 5 = 9 or x + 5 = - 9
• x = 4 or x = - 14