The expression $\frac{1}{x+y}$ is equal to which quantities?

$\frac{1}{x}+y$

$(\frac{1}{x})+y$

$\frac{1}{x+y}$

Incorrect

The expression $a-(b+c)$ is equal to which quantities?

$a-b-c$

$a-b+c$

$(a-b)+c$