Coordinate geometry: finding the ratio in which a line segment is divided by a line The question is:

Determine the ratio in which the line $3x + 4y - 9 = 0$  divides the line segment joining the points $A(1,3)$ and $B(2,7)$.

When I tried solving the question using section formula, which is:
 If $P$ divides the line  segment $A(x,y) B(p,q)$ in ratio $m:n$, then coordinates of $P$ are given by $$\left\lbrace \frac{mp + nx}{m+n}, \frac{mq + ny}{m+n} \right\rbrace.$$
I got the answer :
$(-6) : 25$
which I think is wrong and I'm not able to confirm it. If someone could show me their solution, I'll be really grateful.

Hint-
Step 1 - Calculate the equation of line joining $(1,3)$ and $(2,7)$.
Step 2 - Find the point of intersection of the two lines.
Step 3 - Find the ratio using the above mentioned formula and you will get the ratio.
The answer that I got is $-6:25$.
