Answer
$-\frac{15}{16}$
Work Step by Step
We are given the expression $xy-x^{2}$. We can plug in the given values to solve for the given expression.
$xy-x^{2}=(-\frac{3}{4})(\frac{1}{2})-(-\frac{3}{4})^{2}=\frac{-3\times1}{4\times2}-(-\frac{3}{4}\times-\frac{3}{4})=-\frac{3}{8}-(\frac{9}{16})=-\frac{3\times2}{8\times2}-\frac{9}{16}=-\frac{6}{16}-\frac{9}{16}=\frac{-6-9}{16}=\frac{-15}{16}=-\frac{15}{16}$