Answer
$-\frac{3}{y+3}$
Work Step by Step
1. LCD of all the fractions is found by multiplying the two denominators $y +3$ and $y$ to get $y(y + 3)$.
2. Multiply the numerators and denominators by the LCD:
$\frac{\frac{1}{y + 3} - \frac{1}{y}}{\frac{1}{y}} = \frac{\left(\frac{1}{y + 3} - \frac{1}{y}\right)\cdot y (y + 3)}{\frac{1}{y} \cdot y (y + 3)}$
3. Distribute to multiply:
$\frac{\left(\frac{1}{y + 3} - \frac{1}{y}\right)\cdot y (y + 3)}{\frac{1}{y} \cdot y (y + 3)} = \frac{\frac{y(y + 3)}{y + 3} - \frac{y (y + 3)}{y}}{\frac{1}{y} y (y+3)}$
$=\frac{y - (y + 3)}{y + 3}$
$=-\frac{3}{y+3}$
