Question

Решите пошагово с объяснением,пожалуйста.

Answer 1

(12-d²)/(d+3)+d-3):(1/(d+3)+d/(d²-9)+5/(3-d))

1.

(12-d²)/(d+3)+d-3=(12-d²+(d+3)(d-3))/(d+3)=(12-d²+d²-9)/(d+3)=3/(d+3).

2.

1/(d+3)+d/(d²-9)+5/(3-d)=1/(d+3)+d/((d-3)(d+3))-5/(d-3)=(d-3+d-5*(d+3)/(d²-9)=

=(d-3+d-5d-15)/(d²-9)=(-3d-18)/(d²-9)=-3*(d+6)/(d²-9).

3.

3/(d+3):(-3*(d+6)/(d²-9))=3*(d+3)(d-3)/(-3*(d+3)(d+6))=-(d-3)/(d+6)=(3-d)/(d+6).