21-7(19-x^2+6)-3x^2+1=0

Solution for 21-7(19-x^2+6)-3x^2+1=0 equation:

Simplifying
21 + -7(19 + -1x2 + 6) + -3x2 + 1 = 0

Reorder the terms:
21 + -7(19 + 6 + -1x2) + -3x2 + 1 = 0

Combine like terms: 19 + 6 = 25
21 + -7(25 + -1x2) + -3x2 + 1 = 0
21 + (25 * -7 + -1x2 * -7) + -3x2 + 1 = 0
21 + (-175 + 7x2) + -3x2 + 1 = 0

Reorder the terms:
21 + -175 + 1 + 7x2 + -3x2 = 0

Combine like terms: 21 + -175 = -154
-154 + 1 + 7x2 + -3x2 = 0

Combine like terms: -154 + 1 = -153
-153 + 7x2 + -3x2 = 0

Combine like terms: 7x2 + -3x2 = 4x2
-153 + 4x2 = 0

Solving
-153 + 4x2 = 0

Solving for variable 'x'.

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

Add '153' to each side of the equation.
-153 + 153 + 4x2 = 0 + 153

Combine like terms: -153 + 153 = 0
0 + 4x2 = 0 + 153
4x2 = 0 + 153

Combine like terms: 0 + 153 = 153
4x2 = 153

Divide each side by '4'.
x2 = 38.25

Simplifying
x2 = 38.25

Take the square root of each side:
x = {-6.184658438, 6.184658438}