7x^2-21=30

Solution for 7x^2-21=30 equation:

Simplifying
7x2 + -21 = 30

Reorder the terms:
-21 + 7x2 = 30

Solving
-21 + 7x2 = 30

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 + 7x2 = 30 + 21

Combine like terms: -21 + 21 = 0
0 + 7x2 = 30 + 21
7x2 = 30 + 21

Combine like terms: 30 + 21 = 51
7x2 = 51

Divide each side by '7'.
x2 = 7.285714286

Simplifying
x2 = 7.285714286

Take the square root of each side:
x = {-2.699206233, 2.699206233}