Question

срооооооочно!!!!!!!!!!!

Answer 1

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

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