1.2x^2+21=51

Solution for 1.2x^2+21=51 equation:

Simplifying
1.2x2 + 21 = 51

Reorder the terms:
21 + 1.2x2 = 51

Solving
21 + 1.2x2 = 51

Solving for variable 'x'.

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

Add '-21' to each side of the equation.
21 + -21 + 1.2x2 = 51 + -21

Combine like terms: 21 + -21 = 0
0 + 1.2x2 = 51 + -21
1.2x2 = 51 + -21

Combine like terms: 51 + -21 = 30
1.2x2 = 30

Divide each side by '1.2'.
x2 = 25

Simplifying
x2 = 25

Take the square root of each side:
x = {-5, 5}