Is y=4x-5 proportional

A proportional relation between two numbers, x and y is when:

y= k*x, where k is a real number.

this is read as "the number y is k times the number x" so y is proportional to x, and the constant of proportionality is k.

The equation in the problem is: y = 4x - 5, here you have an x-intercept equal to -5, this quantity breaks the proportionality relation. So in this case y is not proportional to x.