3x+4+9x+2=90

Solution for 3x+4+9x+2=90 equation:

Simplifying
3x + 4 + 9x + 2 = 90

Reorder the terms:
4 + 2 + 3x + 9x = 90

Combine like terms: 4 + 2 = 6
6 + 3x + 9x = 90

Combine like terms: 3x + 9x = 12x
6 + 12x = 90

Solving
6 + 12x = 90

Solving for variable 'x'.

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

Add '-6' to each side of the equation.
6 + -6 + 12x = 90 + -6

Combine like terms: 6 + -6 = 0
0 + 12x = 90 + -6
12x = 90 + -6

Combine like terms: 90 + -6 = 84
12x = 84

Divide each side by '12'.
x = 7

Simplifying
x = 7