3x^2+5u+6=0

Solution for 3x^2+5u+6=0 equation:

Simplifying
3x2 + 5u + 6 = 0

Reorder the terms:
6 + 5u + 3x2 = 0

Solving
6 + 5u + 3x2 = 0

Solving for variable 'u'.

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

Add '-6' to each side of the equation.
6 + 5u + -6 + 3x2 = 0 + -6

Reorder the terms:
6 + -6 + 5u + 3x2 = 0 + -6

Combine like terms: 6 + -6 = 0
0 + 5u + 3x2 = 0 + -6
5u + 3x2 = 0 + -6

Combine like terms: 0 + -6 = -6
5u + 3x2 = -6

Add '-3x2' to each side of the equation.
5u + 3x2 + -3x2 = -6 + -3x2

Combine like terms: 3x2 + -3x2 = 0
5u + 0 = -6 + -3x2
5u = -6 + -3x2

Divide each side by '5'.
u = -1.2 + -0.6x2

Simplifying
u = -1.2 + -0.6x2