2/5r = 8....Help Please?!?!?!?!?!?

2/5(r) = 8
2r/5 = 8
2r = 5(8)
r = 40/2
r = 20

r=8*5/2
r=40/2
r=20

It is not clear if the r is in the denominator or the numerator.
If r is in the denominator: 2/5r = 8
Multiply both sides by 5r,
5r(2/5r) = 5r(8)
2 = 40r
Divide both sides by 40,
2/40 = 40r/40
r = 1/20

If r is in the numerator: (2/5)r = 8
Multiply both sides by 5,
5(2/5)r = 5(8)
2r = 40
Divide both sides by 2,
2r/2 = 40/2
r = 20

First of all the question must be presented clearly to avoid confusion.
To do so brackets are required.
Will assume that you in fact mean :-

(2/5) r = 8

2r = 40

r = 20

2/5r = 8

multiply both sides by 5r

5r(2/5r) = 8(5r)

2=40r

r=2/40

r=1/20

r=20?

2/5 = .4
.4 x20 = 8

green?