5x means 5 times x where x is some placeholder for a number. To get the inverse, we undo the multiplication. Division is the opposite of multiplication. So we'll divide both sides by 5 as one of the steps. Also, we'll swap x and y
y = 5x
x = 5y ... swap x and y
5y = x
5y/5 = x/5 .... divide both sides by 5
y = x/5
So this means the inverse function is equal to x/5