138.40+.20=a

Solution for 138.40+.20=a equation:

Simplifying
138.40 + 0.20 = a

Combine like terms: 138.40 + 0.20 = 138.6
138.6 = a

Solving
138.6 = a

Solving for variable 'a'.

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

Add '-1a' to each side of the equation.
138.6 + -1a = a + -1a

Combine like terms: a + -1a = 0
138.6 + -1a = 0

Add '-138.6' to each side of the equation.
138.6 + -138.6 + -1a = 0 + -138.6

Combine like terms: 138.6 + -138.6 = 0.0
0.0 + -1a = 0 + -138.6
-1a = 0 + -138.6

Combine like terms: 0 + -138.6 = -138.6
-1a = -138.6

Divide each side by '-1'.
a = 138.6

Simplifying
a = 138.6