#### Answer

$\frac{1}{28}$

#### Work Step by Step

-$\frac{3}{4}$ - $\frac{1}{14}$ +$\frac{6}{7}$=
LCD (4,14,7) is 392
-$\frac{3}{4}$$\times$ $\frac{98}{98}$ - $\frac{1}{14}$$\times$ $\frac{28}{28}$ + $\frac{6}{7}$$\times$$\frac{56}{56}$=
=-$\frac{294}{392}$ - $\frac{28}{392}$ +$\frac{336}{392}$=
=$\frac{-294 - 28 + 336}{392}$ =$\frac{14}{392}$=$\frac{14}{14\times28}$=$\frac{1}{28}$