Answer:
D. -15x + 28y
Step-by-step explanation:
- 3x + 7y + 21y - 12x
Move the equation
- 3x - 12x + 7y + 21y
Combine - 3x and - 12x
- 15x + 7y + 21y
Combine 7y and 21y
-15x + 28y
Because you cannot simplify this equation any further, that is your answer
I hope that this helps! :)
