55-13=X

Solution for 55-13=X equation:

Simplifying
55 + -13 = X

Combine like terms: 55 + -13 = 42
42 = X

Solving
42 = X

Solving for variable 'X'.

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

Add '-1X' to each side of the equation.
42 + -1X = X + -1X

Combine like terms: X + -1X = 0
42 + -1X = 0

Add '-42' to each side of the equation.
42 + -42 + -1X = 0 + -42

Combine like terms: 42 + -42 = 0
0 + -1X = 0 + -42
-1X = 0 + -42

Combine like terms: 0 + -42 = -42
-1X = -42

Divide each side by '-1'.
X = 42

Simplifying
X = 42