Выполните действие 1) (х+у)(х-у)= 2) (Р+Т)(Р-Т)= 3)(m+5)(m-5) 4)(n+1)(n-1) 5)(5a-b)(5a+b) 6)(2m+3)(2m-3) 7)(2a-3b)(3b+2a) 8)(7m+3n)(7m-3n) 9)(7m+3n)(7m-3n)
1) х^2-ху+ух-у^2 2) Р^2-РТ+ТР-Т^2 3) m^2-5m+5m-25 4) n^2-n+n-1 5) 25a^2+5ab-5ab-b^2 6) 4m^2-6m+6m-9 7) 6ab-4a^2-9b^2-6ab 8) 49m^2-21mn+21mn-9n^2 9) 49m^2-21mn+21mn-9n^2