1n*3n-0.75=90

Solution for 1n*3n-0.75=90 equation:

Simplifying
1n * 3n + -0.75 = 90

Reorder the terms for easier multiplication:
1 * 3n * n + -0.75 = 90

Multiply 1 * 3
3n * n + -0.75 = 90

Multiply n * n
3n2 + -0.75 = 90

Reorder the terms:
-0.75 + 3n2 = 90

Solving
-0.75 + 3n2 = 90

Solving for variable 'n'.

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

Add '0.75' to each side of the equation.
-0.75 + 0.75 + 3n2 = 90 + 0.75

Combine like terms: -0.75 + 0.75 = 0.00
0.00 + 3n2 = 90 + 0.75
3n2 = 90 + 0.75

Combine like terms: 90 + 0.75 = 90.75
3n2 = 90.75

Divide each side by '3'.
n2 = 30.25

Simplifying
n2 = 30.25

Take the square root of each side:
n = {-5.5, 5.5}