9514 1404 393
Answer:
- wrong: -2x² -x² ⇒ -2x²
- correct: x³ -3x² +6
Step-by-step explanation:
The point of these "what was done wrong" exercises is to see if you know what the correct steps look like.
On line 2, Danielle correctly distributed the minus sign to eliminate the second set of parentheses. (There is often a problem with minus signs and parentheses, so it is nice to see it done correctly.)
On line 3, the two x² terms are incorrectly combined. It looks as though Danielle simply dropped the -x² term because it disappeared without changing the coefficient of x² from -2x². The correct sum of those terms is ...
-2x² -x² = -3x²
so the correct work on line 3 is ...
x³ -3x² +6
