The soluions are approximately x ∈ {0.5, 7.8}.
6, 12, 18
..................
X + x + x + x - 20 is equivalent to 4x - 20 because you can add the like terms, or the x's.
Answer: -(x + 3)^2 = 3
Explanation:
-x^2 - 6x + 6 = 0
-x^2 - 6x = -6
-x^2 - 6x + 9 = -6 + 9
-(x + 3)^2 = 3