18.6+x+(x-5.5)=51.3

Solution for 18.6+x+(x-5.5)=51.3 equation:

Simplifying
18.6 + x + (x + -5.5) = 51.3

Reorder the terms:
18.6 + x + (-5.5 + x) = 51.3

Remove parenthesis around (-5.5 + x)
18.6 + x + -5.5 + x = 51.3

Reorder the terms:
18.6 + -5.5 + x + x = 51.3

Combine like terms: 18.6 + -5.5 = 13.1
13.1 + x + x = 51.3

Combine like terms: x + x = 2x
13.1 + 2x = 51.3

Solving
13.1 + 2x = 51.3

Solving for variable 'x'.

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

Add '-13.1' to each side of the equation.
13.1 + -13.1 + 2x = 51.3 + -13.1

Combine like terms: 13.1 + -13.1 = 0.0
0.0 + 2x = 51.3 + -13.1
2x = 51.3 + -13.1

Combine like terms: 51.3 + -13.1 = 38.2
2x = 38.2

Divide each side by '2'.
x = 19.1

Simplifying
x = 19.1