I think first you need to get it to y equal first take away 4x form both sides then divide by -5 then what ever is beside the x is the x intercept I hope I helped

4x - 5y = 20 (your equation)

4x/20 - 5y/20 = 1 (divide both sides by 20. This puts the equation in what I would call "intercept form".)

x/5 - y/4 = 1 (simplify)

x/5 + y/(-4) = 1 (go the last step)

"Intercept form" is this:

x/(x-intercept) + y/(y-intercept) = 1

We immediately recognize that

x-intercept = 5

y-interctpt = -4

4x/20 - 5y/20 = 1 (divide both sides by 20. This puts the equation in what I would call "intercept form".)

x/5 - y/4 = 1 (simplify)

x/5 + y/(-4) = 1 (go the last step)

"Intercept form" is this:

x/(x-intercept) + y/(y-intercept) = 1

We immediately recognize that

x-intercept = 5

y-interctpt = -4