How much less is two fifths of a ton than one half of a ton

How much less is two fifths of a ton than one half of a ton

1 / 2-2 / 5 = 1 / 10 ton

What's two fifths of one half

1/5

Solution ratio X: 3.5 = 1.4:5.6, half: one fifth = x: one tenth, 36 = 1.2:5, two fifths = 10: two sevens
x: 4 = 0.36:0.9 x 14 = 21 / 4 tonight!

It's very easy to calculate. I'm slow in typing. I'd like to tell you the method. It's very simple
There is a formula in proportion formula, the product of inner term is equal to the product of outer term
x: 5 = 1.4:5.6
If x * 5.6 = 3.5 * 1.4, then x = 0.875
If you don't know anything, you are welcome to ask

X-two fifths x-25x = one half

x-(2/5)x-25x=1/2
-(122/5)x=1/2
x=-5/244