Answer: x = -10 or 2
Explanation:
Given:
√20 - 8x = x
Step 1: Square √20 - 8x
(√20 - 8x)² = (x)²
20 - 8x = x²
Now we can solve the problem
Step 2: Move 20 - 8x to the other side
20 - 8x = x²
-20 + 8x - 20 + 8x
0 = x² + 8x - 20
This is a quadratic equation
Step 3: Factor the quadratic equation
10(-2) = -20 and 10 - 2 = 8
So our factors are 10 and -2
(x + 10)(x - 2) = 0
Step 4: Create a FOIL equation
For this equation to be true, x would have to make either one of the parenthysis equal to zero
(x + 10)(x - 2)
x = -10 x = 2
10 - 10 equals zero, and -2 + 2 equals zero, so those are your answers.