75-3,75=71,25
2/3-2=-1.1/3
5.1/2*2/11=11/2*2/11=1
1/3+1/5=8/15
2/3-2/15=(10-2)/15=8/15
(с+d)^2=c^2+2cd+d^2
(2+х)^2=4+4х+х^2
(х-у)^2=х^2-2ху+у^2
(х+1)^2=х^2+2х+1
(g+2p)^2=g^2+4gp+4p^2
(6а-4в)^2=36а^2-48ав+16в^2
(3х+2у)^2=9х^2+12ху+4у^2
(5z-1)^2=25z^2-10z+1