1.(f+g)(x) = This is fairly simple, all you do is add the two problems.
x2 + 7x + 12 + x2 + 8x + 16
2x2+15x+28
2.(f-g)(x) = Same thing here, just subtract the two equations.
x2 + 7x + 12 - x2 + 8x + 16
-x-4
3.(f•g)(x) =
x4+15x3+84x2+208x+192
4.(f/g)(x) =
x+3/x+4
This is all combining like terms and simplifing. I highly recommend you use www.mathway.com to help you.
Hope this helps! Have a great day!!!