(5c+7d)^2-70cd= (8m-n)^2-64m= (3a-b)(3a+b)+b^2= 9x^2-(y+4x)(y-4x)= (5c-6d)(5c+6d)-25c^2= (7m-10n)(7m+10n)-100^2= 2(a-2)(a+2)= x(x+4)(x-4)= 5c(c+3)(c-3)= 7d^2(d-1)(d+1)=

(5c+7d)^2-70cd=25c^2+70cd+49d^2-70cd=25c^2+49d^2(8m-n)^2-64m=64m^2-16mn+n^2-64m=64m^2-80mn+n^2 (3a-b)(3a+b)+b^2=9a^2-b^2+b^2=9a^2 9x^2-(y+4x)(y-4x)=9x^2-y^2+16x^2=25x^2-y^2 (5c-6d)(5c+6d)-25c^2=25c^2-36d^2-25c^2=-36d^2 (7m-10n)(7m+10n)-100n^2=49m^2-100n^2-100n^2=49m^2-200n^2 2(a-2)(a+2)=9(a^2-4)=9a^2-36 x(x+4)(x-4)=x(x^2-16)=x^3-16x 5c(c+3)(c-3)=5c(c^2-9)=5c^3-45c 7d^2(d-1)(d+1)=7d^2(d^2-1)=7d^4-7d^2 если есть ошибки без обид