(5\frac{1}{2})^2=5^2+2*5*\frac{1}{2}+(\frac{1}{2})^2=25+5+\frac{1}{4}=30\frac{1}{4}
(4\frac{1}{2})^2=(4+\frac{1}{2})^2=4^2+2*4*\frac{1}{2}+(\frac{1}{2})^2=16+4+\frac{1}{4}=20\frac{1}{4}
(10\frac{1}{5})^2=(10+\frac{1}{5})^2=10^^2+2*10*\frac{1}{5}+(\frac{1}5)^2=100+4+\frac{1}{25}=104\frac{1}{25}
(8\frac{2}{3})^2=(9-\frac{1}{3})^2=9^2-2*9*\frac{1}{3}+(\frac{1}{3})^2=81-6+\frac{1}{9}=75\frac{1}{9}
(4\frac{4}{5})^2=(5-\frac{1}{5})^2=5^2-2*5*\frac{1}{5}+(\frac{1}{5})^2=25-2+\frac{1}{25}=23\frac{1}{25}
(99\frac{9}{10})^2=(100-\frac{1}{10})^2=100^2-2*100*\frac{1}{10}+(\frac{1}{10})^2=10000-20+\frac{1}{100}=9980\frac{1}{100}
(10\frac{3}{4})^2=(11-\frac{1}{4})^2=11^2-2*11*\frac{1}{4}+(\frac{1}{4})^2=121-5\frac{1}{2}+\frac{1}{16}=115\frac{1}{2}+\frac{1}{16}=115\frac{8}{16}+\frac{1}{16}=115\frac{9}{16}
82^2-118^2=(82+118)(82-118)=200*(-36)=-7200
77^2-23^2=(77+23)(77-23)=100*54=5400
275^2-25^2=(275+25)(275-25)=300*250=75000
(0,9)^2-(1,1)^2=(0,9+1,1)(0,9-1,1)=2*(-0,2)=-0,4
Źle odczytałam. Zadania były trudne do odczytania.
(4\frac{1}{4})^2=(4+\frac{1}{4})^2=4^2+2*4*\frac{1}{4}+(\frac{1}{4})^2=16+2+\frac{1}{16}=18\frac{1}{16}