n*n-1=90

Solution for n*n-1=90 equation:

Simplifying
n * n + -1 = 90

Multiply n * n
n2 + -1 = 90

Reorder the terms:
-1 + n2 = 90

Solving
-1 + n2 = 90

Solving for variable 'n'.

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

Add '1' to each side of the equation.
-1 + 1 + n2 = 90 + 1

Combine like terms: -1 + 1 = 0
0 + n2 = 90 + 1
n2 = 90 + 1

Combine like terms: 90 + 1 = 91
n2 = 91

Simplifying
n2 = 91

Take the square root of each side:
n = {-9.539392014, 9.539392014}