-2x^2-3+20=0

Solution for -2x^2-3+20=0 equation:

Simplifying
-2x2 + -3 + 20 = 0

Reorder the terms:
-3 + 20 + -2x2 = 0

Combine like terms: -3 + 20 = 17
17 + -2x2 = 0

Solving
17 + -2x2 = 0

Solving for variable 'x'.

Move all terms containing x to the left, all other terms to the right.

Add '-17' to each side of the equation.
17 + -17 + -2x2 = 0 + -17

Combine like terms: 17 + -17 = 0
0 + -2x2 = 0 + -17
-2x2 = 0 + -17

Combine like terms: 0 + -17 = -17
-2x2 = -17

Divide each side by '-2'.
x2 = 8.5

Simplifying
x2 = 8.5

Take the square root of each side:
x = {-2.915475947, 2.915475947}