1
а)8fg^5/6f³g³=4g²/3f²
б)(ut-t)/t³=t(u-1)/t³=(u-1)/t²
в)(9f²-g²)/(3f-g)=(3f-g)(3f+g)/(3f-g)=3f+g
2
а)3/a+(a-3)/(a+5)=[3(a+5)+a(a-3)]/[a(a+5)]=(3a+15+a²-3a)/[a(a+5)]=
=(a²+15)/(a²+5a)
б)3b²/(b-3)(b+3)-3b/(b+3)=(3b²-3b²+9b)/(b²-9)=9b/(b²-9)
в)5u/(u-v)-5=(5u-5u+5v)/(u-v)=5v/(u-v)
3
7/(b+4)²-7/(b-4)(b+4)-7/(b+4)=7(b-4-b-4-b²+16)/[(b+4)²(b-4)]=
=7(-b²+8)/[(b+4)²(b-4)]
4
(4d-4c+dv-cv)/(v²-16)=[4(d-c)+v(d-c)]/(v²-16)=(d-c)(4+v)/[(v-4)(v+4)]=
=(d-c)/(v-4)
d=4;c=2;v=3
(4-2)/(3-4)=2/(-1)=-2