-17.2=13.0+a

Solution for -17.2=13.0+a equation:

Simplifying
-17.2 = 13.0 + a

Solving
-17.2 = 13.0 + 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.
-17.2 + -1a = 13.0 + a + -1a

Combine like terms: a + -1a = 0
-17.2 + -1a = 13.0 + 0
-17.2 + -1a = 13.0

Add '17.2' to each side of the equation.
-17.2 + 17.2 + -1a = 13.0 + 17.2

Combine like terms: -17.2 + 17.2 = 0.0
0.0 + -1a = 13.0 + 17.2
-1a = 13.0 + 17.2

Combine like terms: 13.0 + 17.2 = 30.2
-1a = 30.2

Divide each side by '-1'.
a = -30.2

Simplifying
a = -30.2