Simplify the expression 5y - 2y + 12.

• A. 3y + 12
• B. 7y + 12
• C. 5y + 12
• D. y + 12

Answer: (A)

Combining like terms is what we’re practicing here. When simplifying, you add or subtract coefficients of terms that have the same variable and exponent. In 5y - 2y + 12, the terms with y are like terms, so you combine 5y and -2y to get 3y. The 12 is a constant and doesn’t have a y, so it stays as +12. Therefore, the expression simplifies to 3y + 12. If you see something like 7y + 12, that would come from treating the subtraction as addition, which isn’t correct here; or 5y + 12 would miss subtracting the 2y, which changes the result.