Ответ:
Объяснение:
1) (x^2-19+10)/(x-3) = (x^2-9)/(x-3)= (x-3)(x+3)/(x-3)= x+3= 77+3=80
2) (y+7-2y-2)/(y^2-25)= (-y+5)/(y^2-25)= - (y-5)/(y-5)(y+5)= -1/(y+5) = -1/(-25,1+5)=
=-1/(-20,1)=1/20,1= 10/201
3) (a^2-43)/(a-6) + 7/(a-6) = (a^2-43+7)/(a-6)= (a^2-36)/(a-6)= (a-6)(a+6)/(a-6)=
=a+6=-10,25+6= -4,25
4) (9b-1-6b+10)/(b^2-9) = (3b+9)/(b-3)(b+3)= 3(b+3)/(b-3)(b+3)= 3/(b-3)=
=3/(-10-3)=3/(-13)=-3/13