Question

How do you do 4/5x-.4 repeating?

Answer 1

We use the algebraic way for this:
0.0¯4=x we manipulate the equation by multiplying it by 10 and 100.
0.¯4=10x
4.¯4=100x
We subtract the second equation from the third equation to get:
4=90x 
Therefore, 
490=x or
245=x
so the answer is

2/45