x^2-7=21

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Solution for x^2-7=21 equation: 


Simplifying
x2 + -7 = 21

Reorder the terms:
-7 + x2 = 21

Solving
-7 + x2 = 21

Solving for variable 'x'.

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

Add '7' to each side of the equation.
-7 + 7 + x2 = 21 + 7

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

Combine like terms: 21 + 7 = 28
x2 = 28

Simplifying
x2 = 28

Take the square root of each side:
x = {-5.291502622, 5.291502622}

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