42-a=-2a+99

Solution for 42-a=-2a+99 equation:

Simplifying
42 + -1a = -2a + 99

Reorder the terms:
42 + -1a = 99 + -2a

Solving
42 + -1a = 99 + -2a

Solving for variable 'a'.

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

Add '2a' to each side of the equation.
42 + -1a + 2a = 99 + -2a + 2a

Combine like terms: -1a + 2a = 1a
42 + 1a = 99 + -2a + 2a

Combine like terms: -2a + 2a = 0
42 + 1a = 99 + 0
42 + 1a = 99

Add '-42' to each side of the equation.
42 + -42 + 1a = 99 + -42

Combine like terms: 42 + -42 = 0
0 + 1a = 99 + -42
1a = 99 + -42

Combine like terms: 99 + -42 = 57
1a = 57

Divide each side by '1'.
a = 57

Simplifying
a = 57