Question

Brainliest to correct answer

Answer 1

The answer is.... B!!

This is the answer because if you fill in X as 4, then you would end up with 16 and the square root of 16 is 4!!

I hope this helps!!

Answer 2

$\sqrt{x+12} =x$

Lets square both sides.

$x+12 = x^2$

We have the pieces of a quadratic equation here, lets move things around to set it up. We can subtract x and 12 from both sides to do this.
$0 = x^2 - x - 12$

Lets factor to find the solutions. We need something that multiplies to -12 and adds to -1. Factors are 1,12 and 3,4. -4 and 3 would work for what we need.
$0 = (x - 4)(x+3)$

This makes our solutions -3 and 4, since those are the numbers that set the equation to 0. Lets return to our original equation and make sure both of these answers are valid. This is necessary because of the properties of square roots.
Plug in 4
$\sqrt{4+12} =4$
$\sqrt{16} =4$
$4 =4$
Our first solution is true. Lets check our second solution.
$\sqrt{-3+12} =-3$

$\sqrt{9} =-3$

$3 =-3$

This solution is not true since 3 does not equal -3. Therefore only our first solution is the answer. The final answer is 4.