x^2-81=42

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Solution for x^2-81=42 equation: 


Simplifying
x2 + -81 = 42

Reorder the terms:
-81 + x2 = 42

Solving
-81 + x2 = 42

Solving for variable 'x'.

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

Add '81' to each side of the equation.
-81 + 81 + x2 = 42 + 81

Combine like terms: -81 + 81 = 0
0 + x2 = 42 + 81
x2 = 42 + 81

Combine like terms: 42 + 81 = 123
x2 = 123

Simplifying
x2 = 123

Take the square root of each side:
x = {-11.090536506, 11.090536506}

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