72=9u-u

Solution for 72=9u-u equation:

Simplifying
72 = 9u + -1u

Combine like terms: 9u + -1u = 8u
72 = 8u

Solving
72 = 8u

Solving for variable 'u'.

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

Add '-8u' to each side of the equation.
72 + -8u = 8u + -8u

Combine like terms: 8u + -8u = 0
72 + -8u = 0

Add '-72' to each side of the equation.
72 + -72 + -8u = 0 + -72

Combine like terms: 72 + -72 = 0
0 + -8u = 0 + -72
-8u = 0 + -72

Combine like terms: 0 + -72 = -72
-8u = -72

Divide each side by '-8'.
u = 9

Simplifying
u = 9