Question

4 times a number is 12 less than the square of that number. Find the positive solution.

Answer 1

Answer:

$x = 6$

Step-by-step explanation:

Given

Let the number be x.

So, we have:

$4 * x$ ----- 4 times a number

$= x^2 - 12$ --- 12 less than its square

The equation becomes

$4x = x^2 - 12$

Equate to o

$x^2 - 4x - 12 = 0$

Split

$x^2 - 6x +2x - 12 = 0$

Factorize

$x(x - 6) +2(x - 6) = 0$

Factor out x - 6

$(x + 2)(x - 6) = 0$

Split

$x + 2 = 0\ or\ x - 6 = 0$

Solve for x

$x = -2\ or\ x = 6$

The positive value is 6