Find the value of x a. 2 b. 4 c. 6 d. 8

Hello from MrBillDoesMath!

Choice B, 4

Discussion:

From the Pythagorean Theorem

x^2 + ( x-2)^2           =    ( sqrt(20) ) ^ 2     =>

x^2 + ( x^2 - 4x + 4) = 20                            => combine common terms

2x^2 -4x + 4 = 20                                        => divide both sides by 2

x^2 -2x + 2 = 10                                           => subtract 10 from both sides

x^2 -2x - 8 = 0                  => x^2 -2x - 8 = (x-4)(x+2)

(x-4)(x+2) = 0                    =>

x = 4, x = -2

The answer is Choice B, 4

Thank you,

MrB