Suppose x can be expressed as a function of y by x = 5x − 3.

a. How can y be expressed as a function of x?
b. What is the relationship between the slopes of the two linear equations?
c. How do the x-intercepts and y-intercepts of the two equations relate?

Do you have a typo?

did you mean:
Suppose x can be expressed as a function of y by x = 5y − 3 ??

If so, then

a) x + 3= 5y
y = (x+3)/5

b) since all I did was to re-arrange the equation, I don't have two equations, it is the same equation.
Of course all properties such as slope, x-intercept, and y-intercept are the same.