10 is the answer hope that's what it was
For one pair of socks you pay $12 plus $2 shipping.
Let's use x as the variable for how many pairs of socks someone might buy.
If someone buys 5 pairs of socks, they will pay $62. $12 * 5 + $2
So, we can write the expression as 12x + 2.
18(y-5)^2=x+3
do the algebra to make it into =x form
x=18y^2-180y+447
then you take the form of the focus, you can do the math
(-215/72, 5)