(k^2+1/2k-1 - k/2) (3-k/k+2 - 1)= -1/2 доказать

Question

(k^2+1/2k-1 - k/2) (3-k/k+2 - 1)= -1/2 доказать

Answer 1

1)(2(k²+1)-k(2k-1))/2(2k-1)=(2k²+2-2k²+k)/2(2k-1)=(k+2)/2(2k-1)
2)(3-k-1(k+2))/(k+2)=(3-k-k-2)/(k+2)=(1-2k)/(k+2)
3)(k+2)/2(2k-1)*(1-2k)/(k+2)=-1/2
-1/2=-1/2