The sum of a positive number and its square is 90. What is the value of the number?
Show answer & explanation
Correct answer: C
Explanation
Given:
Number + Its Square = 90
According to the formula:
Let the number be x.
x + x² = 90
x² + x − 90 = 0
(x + 10)(x − 9) = 0
x = 9