а) 143^2 - 142^2 = (143 - 142 )*(143 + 142) = 1* 285 = 285
б)157^2 + 2•157•43+43^2 = (157 +43)^2 = 200^2 = 40000
в)173^2-2•173•73+73^2 = (173 - 73)^2 = 100^2 = 10000
а) 143^2 - 142^2 = (143 - 142 )*(143 + 142) = 1* 285 = 285
б)157^2 + 2•157•43+43^2 = (157 +43)^2 = 200^2 = 40000
в)173^2-2•173•73+73^2 = (173 - 73)^2 = 100^2 = 10000