#### Answer

$x=\frac{a-c+am}{m}$.

#### Work Step by Step

We start by multiplying both sides by $x-a$ and distributing. We have $a-c=m(x-a)$ is $a-c=mx-am$. Now, we add $am$ to both sides to isolate x with its coefficient. We have $a-c+am=mx$. Finally, we divide both sides by m to get $\frac{a-c+am}{m}=x$.