-21x^2+28=

Solution for -21x^2+28= equation:

Simplifying
-21x2 + 28 = 0

Reorder the terms:
28 + -21x2 = 0

Solving
28 + -21x2 = 0

Solving for variable 'x'.

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

Add '-28' to each side of the equation.
28 + -28 + -21x2 = 0 + -28

Combine like terms: 28 + -28 = 0
0 + -21x2 = 0 + -28
-21x2 = 0 + -28

Combine like terms: 0 + -28 = -28
-21x2 = -28

Divide each side by '-21'.
x2 = 1.333333333

Simplifying
x2 = 1.333333333

Take the square root of each side:
x = {-1.154700538, 1.154700538}