Answer:
Is this a multiple choice?
Step-by-step explanation:
a b
3x^2 - 10x - y
2x - 8y + 3x^2 +7y -12x
can not combine unlike terms so 3x^2 stays alone
2x - 12x = -10 x
-8y +7y = -y
See attachment
Idaho Falls, Idaho -17°