Tìm x, biết

Tìm x, biết 
a, $\left(-1\frac{1}{5}\right)$:$\left(-3\frac{3}{5}\right)$=$\frac{-7}{4}+\frac{1}{4}:\frac{11}{8}$
​b,$7,5x:$$\left(5\frac{195}{315}-8\right)$=$2\frac{13}{15}$
c,$60\% x+$$\frac{2}{3} x+x=688$
d,$1-$$\left(5\frac{3}{8}-x-7\frac{5}{24}\right)$:$16\frac{2}{3}=0$