10.50+a*.15=55.50

Solution for 10.50+a*.15=55.50 equation:

Simplifying
10.50 + a * 0.15 = 55.50

Reorder the terms for easier multiplication:
10.50 + 0.15a = 55.50

Solving
10.50 + 0.15a = 55.50

Solving for variable 'a'.

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

Add '-10.50' to each side of the equation.
10.50 + -10.50 + 0.15a = 55.50 + -10.50

Combine like terms: 10.50 + -10.50 = 0.00
0.00 + 0.15a = 55.50 + -10.50
0.15a = 55.50 + -10.50

Combine like terms: 55.50 + -10.50 = 45
0.15a = 45

Divide each side by '0.15'.
a = 300

Simplifying
a = 300