Identify like terms. Numbers that have no variables, such as 5 and 68, are like terms. Variables of the same letter are like terms, such as 6x and -9x. Variables of the same letter that are raised to the same power are like terms. Examples include 5y^2, y^2 and -9y^2.
Group like terms together within parentheses. For example, if you have 5a + 3a^2 - 7 + 4a^2 - a + 10, you would group like terms together as follows: (3a^2 + 4a^2) + (5a - a) + (-7 + 10).
Change the sign of any value that you move across an equals sign. For instance, if you have 5x - 5 = 4x - 4, you would regroup the equation as follows: (5x - 4x) = (5 - 4).
Perform the mathematical operations as indicated by the signs. For instance, the example in Step 2 was (3a^2 + 4a^2) + (5a - a) + (-7 + 10). You would add the terms in the first parentheses to get 7a^2. Then you would subtract "a" from 5a to get 4a in the second set of parentheses. In the third set, you would add -7 to 10 to get 3. Therefore, your final expression would be 7a^2 + 4a + 3.