6=3+u

Solution for 6=3+u equation:

Simplifying
6 = 3 + u

Solving
6 = 3 + u

Solving for variable 'u'.

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

Add '-1u' to each side of the equation.
6 + -1u = 3 + u + -1u

Combine like terms: u + -1u = 0
6 + -1u = 3 + 0
6 + -1u = 3

Add '-6' to each side of the equation.
6 + -6 + -1u = 3 + -6

Combine like terms: 6 + -6 = 0
0 + -1u = 3 + -6
-1u = 3 + -6

Combine like terms: 3 + -6 = -3
-1u = -3

Divide each side by '-1'.
u = 3

Simplifying
u = 3