Linear equations and like terms
Collect the variable terms on one side and the numbers on the other, then divide by the coefficient.
A worked example
Solve 6x + 5 = 2x + 29. Subtract 2x to get 4x + 5 = 29, subtract 5 to get 4x = 24, then divide by 4, so x = 6.
The mistake people actually make
Only like terms combine, so 4x and 7 cannot be added together. A term moved across the equals sign changes its sign.