0=x^2+-21.75+15.75

Solution for 0=x^2+-21.75+15.75 equation:

Simplifying
0 = x2 + -21.75 + 15.75

Reorder the terms:
0 = -21.75 + 15.75 + x2

Combine like terms: -21.75 + 15.75 = -6
0 = -6 + x2

Solving
0 = -6 + x2

Solving for variable 'x'.

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

Add '-1x2' to each side of the equation.
0 + -1x2 = -6 + x2 + -1x2
Remove the zero:
-1x2 = -6 + x2 + -1x2

Combine like terms: x2 + -1x2 = 0
-1x2 = -6 + 0
-1x2 = -6

Divide each side by '-1'.
x2 = 6

Simplifying
x2 = 6

Take the square root of each side:
x = {-2.449489743, 2.449489743}