I need help I don’t know how that’s not right.

Answer: v=-81.92
Step-by-step explanation:
[tex]\displaystyle\\7+\frac{v}{8} =-3.24\\\\7+\frac{v}{8}-7 =-3.24-7\\\\\frac{v}{8} =-10.24\\\\\frac{v}{8} =-10.24[/tex]
Multiply both parts of the equation by 8:
[tex]\displaystyle\\(\frac{v}{8})(8)=(-10.24)(8) \\\\v=-81.92[/tex]