Subject: Algebra

Dear Math Central,

My name is Stephanie. My grade 7 class is doing some strange form of algebra which I've never done nor seen before. We are doing equations like these: 3y - 6 + 7 - 4y = 6y - 6. I don't really understand them and was wondering if you could help me do my homework and explain how to at the same time. It would be really great if you could!!!!! Thank you so much! -Stephanie

1. -9x - 5 - 8 + x = ?
   
   
2. 5 + 6x - 3y + x + 8y = ?
   
   
3. -x - 3 + 5x + 6y + 8x - 9= ?

I will do the second problem and see if that helps. In this expression you have three kinds of quantities. There is a number 5, some x's 6x + x and some y's, -3y + 8y, that is a 5, 7x's and 5y's. This is what your teacher probably calls "collecting like terms". In the more usual way of writing it