Answer
$\frac{9x-7y}{x^{2}y}$
Work Step by Step
First, we will find the LCM of the two denominators. Upon inspection, we find that $xy^{2}$ is the lowest number that is a multiple of $x^{2}$ and xy.
Therefore, $-\frac{7}{x^{2}}+\frac{9}{xy}=\frac{-7(y)+9(x)}{x^{2}y}$
Now, we will simplify the expression:
Step 1: $\frac{-7(y)+9(x)}{x^{2}y}$
Step 2: $\frac{-7y+9x}{x^{2}y}$
Step 3: $\frac{9x-7y}{x^{2}y}$
