I don’t know the answer sorry
If you graph out y = x^2 - 1, you'll see that it is a curved parabola. It is not a straight line. So visually this shows the equation is not linear. It's considered nonlinear.
Algebraically, the given equation does not fit the form y = mx+b which is slope intercept form. So this is more confirmation that we do not have a linear function.
4/3 can be written as 4:3 or 4/3 and is a real number
$0.25 you just have to multiply .65 times 5 for site A which is $3.25 and for sure b just plug in 5 for x and multiply by .60 which gives you $3.00 so site A gives you $0.25 more
