3x²+11x-4=3(x+4)(x-1/3)=(x+4)(3x-1)
D=121+18=169
x1=(-11-13)/6=-4
x2=(-11+13)/6=1/3
1)(x-4)/(x+4)(3x-1)+16/(x-4)(x+4)=((x-4)²+16(3x-1))/(x²-16)(3x-1)=
=(x²-8x+16+48x-16)/(x²-16)(3x-1)=(x²+40x)/(x²-16)(3x-1)=x(x+40)/(x²-16)(3x-1)
2)(x+40)/(x³-16): x(x+40)/(x²-16)(3x-1)=(x+40)/(x³-16)* (x²-16)(3x-1)/x(x+40)=
=(x²-16)(3x-1)/x(x³-16)