coordinates

substitute the slope for m: $y = {3 \over 7}x + b$.

Now, plug in the point $(14,8)$ and solve for b: $8 = {3 \over 7} \times 14 + b$.

Solving for b, we find $b = 2$, so our answer is $\color{brown}\boxed{y = {3 \over 7}x + 2}$