Answer
$n=-28$
Work Step by Step
We are trying to solve for the given variable so that the proportion is true.
To determine if a proportion is true, we have to find if the cross products are equal.
The cross products of $\frac{a}{b}=\frac{c}{d}$ are $a \cdot d$ and $b \cdot c$.
$25*n=-7*100$
$25n=-700$
$25n\div25=-700\div25$
$n=-28$