Answer:
-4x³y - 7xy² + 4y
Step-by-step explanation:
See the numbered steps below with the solution.
Step 1. Get rid of the first set of parentheses. It is unnecessary. To get rid of the second set of parentheses, since there is a negative sign to its left, change every sign inside the parentheses.
Step 2. Group together the like terms.
Step 3. Combine like terms.
Solution:
(3x³y − 9xy² + 2y) − (7x³y − 2xy² − 2y) =
Step 1. = 3x³y − 9xy² + 2y − 7x³y + 2xy² + 2y
Step 2. = 3x³y - 7x³y - 9xy² + 2xy² + 2y + 2y
Step 3. = -4x³y - 7xy² + 4y
Answer: -4x³y - 7xy² + 4y
