x^2+3a-90=0

Solution for x^2+3a-90=0 equation:

Simplifying
x2 + 3a + -90 = 0

Reorder the terms:
-90 + 3a + x2 = 0

Solving
-90 + 3a + x2 = 0

Solving for variable 'a'.

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

Add '90' to each side of the equation.
-90 + 3a + 90 + x2 = 0 + 90

Reorder the terms:
-90 + 90 + 3a + x2 = 0 + 90

Combine like terms: -90 + 90 = 0
0 + 3a + x2 = 0 + 90
3a + x2 = 0 + 90

Combine like terms: 0 + 90 = 90
3a + x2 = 90

Add '-1x2' to each side of the equation.
3a + x2 + -1x2 = 90 + -1x2

Combine like terms: x2 + -1x2 = 0
3a + 0 = 90 + -1x2
3a = 90 + -1x2

Divide each side by '3'.
a = 30 + -0.3333333333x2

Simplifying
a = 30 + -0.3333333333x2