Rewrite the equation so both sides have the same base, then equate exponents and solve for c.
[tex]\displaystyle\left(\frac{1}{4}\right)^{c-2}=64\\\\\left(4^{-1}\right)^{c-2}=4^{3}\\\\-(c-2)=3\\\\-1=c[/tex]
The value of c is -1.
