–3(–4y + 3) + 7y
Combine like terms

Question

–3(–4y + 3) + 7y 
Combine like terms

anonymous · Answer

is the answer 19y^2 - 3 or 19y -9 ?

debbieg · Answer

Which do you think? :)

anonymous · Answer

those are both the answers I came up with... i just solved the problem two different ways hahaha I'm not sure which way is the right way to solve it

debbieg · Answer

OK, well.... one of the ways you did it is right and one is wrong. :) Here is the right way:

–3(–4y + 3) + 7y      distribute
= 12y - 9 + 7y         put like terms together 
= 12y + 7y -9         add like terms
= 19y - 9

You can't get a y^2 term from there, because there is NOWHERE that you are multiplying that y by another factor of y. And I have no idea where the -3 would come from either.... so whatever you did to get THAT answer is wrong. If you want to show me what you did, I can walk you through where your error is.

anonymous · Answer

I distributed the -3 at the beginning

debbieg · Answer

ok, that's correct - you should get 12y - 9 + 7y

and then?

anonymous · Answer

Ohhhhhh I see what I did! I forgot to distribute the -3 to the positive 3 lol

debbieg · Answer

OK, that still doesn't explain how you had a -3 instead of 3 (I guess you distributed the "-" but not the 3? lol) or how you got the y^2... you can't get y^2 from y, unless you multiply by another y. :) But as long as you see what you did wrong and won't do it next time, that's all that matters!!  :)

debbieg · Answer

Oh, I think you added 12y + 7y and made it 19y^2? but you see why that doesn't work now, right? :) When you add like terms, you JUST add together the coefficients!

anonymous · Answer

Haha yes thats exactly what I did.. thank you :)

debbieg · Answer

you're welcome. :)