Triangle xy z is similar to triangle pqr
solve for k.
k=
19.5
10.5
r
5.5

We can write a proportion between short and long legs:

Solving for k yields

a

step-by-step explanation:

check above link.

graphically?   well, you graph them both, the solutions is where they both intersect each other, since there are two solutions, meaning they will meet twice, or namely the linear will run into the quadratic curve twice, and where they meet, those x,y coordinates are the solutions to the system.