90=n+n-1

Solution for 90=n+n-1 equation:

Simplifying
90 = n + n + -1

Reorder the terms:
90 = -1 + n + n

Combine like terms: n + n = 2n
90 = -1 + 2n

Solving
90 = -1 + 2n

Solving for variable 'n'.

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

Add '-2n' to each side of the equation.
90 + -2n = -1 + 2n + -2n

Combine like terms: 2n + -2n = 0
90 + -2n = -1 + 0
90 + -2n = -1

Add '-90' to each side of the equation.
90 + -90 + -2n = -1 + -90

Combine like terms: 90 + -90 = 0
0 + -2n = -1 + -90
-2n = -1 + -90

Combine like terms: -1 + -90 = -91
-2n = -91

Divide each side by '-2'.
n = 45.5

Simplifying
n = 45.5