ok ummm help me do this question!
What are you trying to do? Do you want to solve for C? If so, then you need the value of F.
If you just want to rearrange this basic unit of temperature conversion equation, then do the following:
$\displaystyle F=\frac{9}{5}C + 32$
$\displaystyle F - 32 = \frac{9}{5}C + 32 - 32$
$\displaystyle F - 32 = \frac{9}{5}C$
$\displaystyle (F - 32) *\frac{5}{9}= \frac{9}{5}C*\frac{5}{9}$
$\displaystyle (F - 32)\frac{5}{9}= C$
$\displaystyle C = \frac{5(F - 32)}{9}$