помогите очень надо .

7
(3b²+25)/(b-5)² +(b+5)/(b-5)=(3b²+25+(b-5)(b+5))/(b-5)²=(3b²+25+b²-25)/(b-5)²=
=4b²/(b-5)²
8
(y-1)/(y+1)+4y/(y-1)(y+1)=(((y-1)²+4y)/(y-1)(y+1)=(y²-2y+1+4y)/(y-1)(y+1)=
=(y²+2y+1)/(y-1)(y+1)=(y+1)²/(y-1)(y+1)=(y+1)/(y-1)

спасибочки

(3b^2 + 25)/(b-5)^2 + (b+5)/(b-5) = (3b^2 + 25 + b^2 - 25)/(b-5)^2 = 4b^2/(b-5)^2

(у-1)/(у+1) + 4у/(у-1)(у+1) = (у+1)^2/(у-1)(у+1) = (у+1)/(у-1)