Question

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

a) –12 or 7
b) –12 or –7
c) –7 or 12
d) 7 or 12

Answer 1

Let the number be x, then (x - 9)^2 = x - 3
x^2 - 18x + 81 = x - 3
x^2 - 19x + 84 = 0
(x - 12)(x - 7) = 0
x = 12 or 7

Answer 2

The number can be 12 or 7, option(D).

What is an equation?

A mathematical statement consisting of an equal symbol between two algebraic expressions with the same value is known as an equation.

Let the number be = x

According to the question:

( x - 9)^2 = x - 3

x^2 - 18x + 81 = x - 3

x^2 - 19x + 84 = 0

x^2 - 12x - 7x + 84 = 0

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

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

x = 7 , 12

Hence the number is either 12 or 7.

Learn more about equations on:

https://brainly.com/question/16450098

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