Answer
$=\frac{2d}{5}$
Work Step by Step
$\frac{d}{5}-(-\frac{d}{5})\longrightarrow$ change subtraction to addition by changing the sign of the following term
$=\frac{d}{5}+\frac{d}{5}\longrightarrow$ add the numerators of like fractions
$=\frac{2d}{5}$
