## Elementary Geometry for College Students (6th Edition)

X ≢ ℝ (All Real Numbers) X $\ne$ 0 X $\ne$ 2
(X+2) x (X-2) = 2X^2 (X+2) x (x-2) - 2x^2 = 0 X^2 - 4 - 2X^2 -X^2 - 4 = 0 X^2 = 4 X = + or - $\sqrt-4$ X ≢ ℝ (All Real Numbers) X $\ne$ 0 X $\ne$ 2 1. Move variable to the left side and change its sign. 2. Using (a-b)(a+b)= a^2-b^2, simplify the product. 3. Collect like terms. 4. Move constant to the right side and change its sign. 5. Change the signs on both sides of the equation. 6. Square root both sides of the equation. 7. The square root of a negative number does not exist in the set of Real Numbers. 8. Exclude the solution equal to any restricted value of x. (X $\ne$ ℝ)