. Find the sum of the following polynomials.
1. 10mn and -15mn ____________________________________________
2. -7a
2
and -8a
2
____________________________________________
3. 6(x+3) and -7(x+3) ____________________________________________
4.
1
4
ab and -
1
4
ab ____________________________________________
5. 0.5 xyz and 1.5 xyz