Answer
$n=37.8$
Work Step by Step
We start with the given equation: $\frac{5}{7}n-12=15$
We add $12$ to both sides of the equation: $$\frac{5}{7}n-12+12=15+12$$$$\frac{5}{7}n=27$$Next, we multiply by the reciprocal of $\frac{5}{7}$, $\frac{7}{5}$, on both sides of the equation: $$\frac{7}{5}\cdot\frac{5}{7}n=27\cdot\frac{7}{5}$$$$n=37.8$$
