Question

срооооооочно!!!!!!!!!!!

Answer 1

$a)frac{1}{2a}+ frac{1}{a}= frac{1}{2a}+frac{2}{2a}=frac{3}{2a}$

$b)frac{3}{3-y}-frac{y}{y^{2}-9}=-frac{3}{y-3}-frac{y}{(y-3)(y+3)}=-frac{3(y+3)+y}{(y-3)(y+3)}=$ $-frac{3y+9+y}{(y-3)(y+3)}=-frac{4y+9}{y^{2}-9}$