Найдем производную f'(x)=(4x (1-7x)-2x^2×(-7))/(1-7x)^2=(14x^2-28x^2+4x)/(1-7x)^2=(4x-14x^2)/(1-7x)^2
f'(1)=(4-14)/(1-7)^2=-10/36=-5/18
найдем производную
f'(x)=((6x^2+6x)(x-1)-(2x^3+3x^2+1))/(x-1)^2=(6x^3+6x^2-6x^2-6x-2x^3-3x^2-1)/(x-1)^2=(4x^3-3x^2-6x-1)/(x-1)^2