5)
=2а^2+4ав+ав+2в^2=
=2а^2+2в^2+5ав
6)
=х^2+2х+х+2=х^2+3х+2
7)
=а^2+2ав+в^2
8)
=3а-а^2-6+2а=5а-а^2-6
9)
=а^2-2ав+в^2
10)
=9х^2+12ху+4у^2
11)
=10мн+20м^2+14н^2+28мн=
=38мн+20м^2+14н^2
12)
=4х^2-9у^2
13)
=-2а^2+3ав-2ав+3в^2=
=-2а^2+ав+3в^2
14)
=а^4+2а^2в^2+в^4
15)
=2х^2у^2+4х^5-у^4-2х^3у^2
16)
=36а^2+60ав+3ав+5в^2=
=36а^2+63ав+5в^2
17)
=15мн-25м^2-6н^2+10мн=
=25мн-25м^2-6н^2
18)
=35х^2-49ху+20ху-28у^2=
=35х^2-29ху-28у^2