Question

The square of 9 less than a number is 3 less than the number. What is the number?

-12 or 7
-12 or -7
-7 or 12
07 or 12

Answer 1

Answer: D

Explanation:

(x-9)² = x-3

(x-9) (x-9)= x-3

x² - 9x-9x +81 = x-3

x² -18x+81 =x-3

x²-19x+84 =0

(x-12)(x-7)=0

x=12 or 7