Решите ! 2а/b -1-6a/b+13-8a/b= 4b-2/3b -2b-1/3b+1/3b= 13х+6y/(х+y)^2 -11х+4y/(х+y)^2=

1)
2а/в-1-6а/в+13-8а/в=2а-1+6а+13-8а/в=12/в
2)
4в-2/3в-2в-1/3в+1/3в=4в-2-2в+1+1/3в=2в/3в=2/3
3)
13х+6у/(х+у)²-11х+4у/(х+у)²=13х+6у-11х-4у/(х+у)²=2х+2у/(х+у)²=2(х+у)/(х+у)²=
2/х+у