25-4х^2+4xy-y^2 = (25-у^2) + (4ху-4х^2) = (5^2 - у^2) + 4х(у-х) = (5-у)(5+у) + 4х(у-х)
64a^4b^2+24a^2b^4 = 8а^2b^2(8a^2 + 3b^2)
25-4х^2+4xy-y^2 = (25-у^2) + (4ху-4х^2) = (5^2 - у^2) + 4х(у-х) = (5-у)(5+у) + 4х(у-х)
64a^4b^2+24a^2b^4 = 8а^2b^2(8a^2 + 3b^2)