pls send me step by step pic

To solve, simply do this:
[tex](\frac{1}{2}^3)-(\frac{3}{4} )^2\\\\\frac{1}{2} *\frac{1}{2} *\frac{1}{2} *\frac{1}{2} \\\\\frac{1}{8} -(\frac{3}{4})^2\\\\\frac{1}{8}-\frac{9}{16}\\\\=\frac{-7}{16}[/tex]
Then you'll get the answer, -7/16