Select all of the values that are solutions of x2 + 20 = 12x. x = - 10 x = - 2 x = 2 x = 10

2 and 10

2, and 10

Step-by-step explanation:

Let's work through each one.

First, plug - 10 into the equation:

-10² + 20 = 12 x - 10?

-10² = 100

100 + 20 = 120

12 x - 10 = - 120

120 = - 120? False!

But, using these same calculations, we can see that 10 is a correct answer.

Because everything's the same up to 12 x 10 = 120.

120 = 120

Same with 2 and - 2

-2 does not work, but 2 does.

2² + 20 = 12 x 2?

4 + 20 = 24?

24 = 24? True!