90=5a+a

Solution for 90=5a+a equation:

Simplifying
90 = 5a + a

Combine like terms: 5a + a = 6a
90 = 6a

Solving
90 = 6a

Solving for variable 'a'.

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

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

Combine like terms: 6a + -6a = 0
90 + -6a = 0

Add '-90' to each side of the equation.
90 + -90 + -6a = 0 + -90

Combine like terms: 90 + -90 = 0
0 + -6a = 0 + -90
-6a = 0 + -90

Combine like terms: 0 + -90 = -90
-6a = -90

Divide each side by '-6'.
a = 15

Simplifying
a = 15