fractional equations

[Dillinger4]

I find that these types of equations arent to difficult to solve but i seem to be stuck. I know that a * 1/k is a/k but i dont know how to apply this to my problem. 16 = 4/5 * x if the problem was stated as 16 = 1/5 * x it would end up as x/5. So how do i convert 16 = 4/5 * x? Is it 4/5 * x = 5x + 4 / 5 ? Thanks for the help.

[sql_lall]

Yeah, some things:
1/5 * x = x/5 BECAUSE (x*1)/5 = x/5
similarly,
4/5 * x = 4x/5 BECAUSE (4*x)/5 = (4x)/5

So, if 16 = 4/5 * x
=> 4x/5 = 16
=> 4x = 16*5=80
=> x = 80/4 = 20

Also, if 4/5 * x = 16
=> 1/5 * x = 4 (divide by 4)
and you only have to use 1/5, which you have displayed how to do.

[Dillinger4]

Ah ok. What was i thinking. Right. 4/5 * x = 4/5 * x/1 = 4x/5
Thanks.