Subtracting Polynomials

2012-04-08144208.jpg picture by King_Bradley - Photobucket

You try 4

First thing I do is distribute the - to the second paranthesis so I get 3h^2-h+4

Then I do

-7h^2-8h+1
PLUS
3h^2-h+4

To get

-4h^2-9h+5

Wrong answer, I try subtracting


-7h^2-8h+1
minus
3h^2-h+4
______________
-10h^2-7h+5

What am I doing wrong?

note that the subtraction changes the sign of each term in the second trinomial ...



combine like terms ...