222=123-y

Solution for 222=123-y equation:

Simplifying
222 = 123 + -1y

Solving
222 = 123 + -1y

Solving for variable 'y'.

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

Add 'y' to each side of the equation.
222 + y = 123 + -1y + y

Combine like terms: -1y + y = 0
222 + y = 123 + 0
222 + y = 123

Add '-222' to each side of the equation.
222 + -222 + y = 123 + -222

Combine like terms: 222 + -222 = 0
0 + y = 123 + -222
y = 123 + -222

Combine like terms: 123 + -222 = -99
y = -99

Simplifying
y = -99