Question

The square of a certain number is 4 less than 4 times that same number. What is the value of the number?

Answer 1

2

Explanation:

Let the number be n.

Then n^2 = 4n - 4.

Rewriting this in the standard form of a quadratic equation, we get

n^2 - 4n + 4 = 0, or (n - 2)(n - 2)= 0. Only the positive root, n = 2, "works" here.

Check: The square of 2 is = 4(2) - 4 is TRUE. The number is 2.