Help with an equation please?

Hi,

I think I'm a bit out of my depth in this forum so forgive me if I've posted in the wrong place - I'm studying accountancy and I have an equation from my study book which I don't understand - I don't know whether it's a differential equation, but I'd be very grateful if somebody could explain it to me.

It goes as follows:

1. 8 = x + 1.2(7-x)
2. 8 = x + 8.4 - 1.2x
3. 0.2x = 0.4
4. x = 2

Can anyone tell me how on earth they get from stage 2 to stage 3? Are there any general tips for how to deal with equations?

Many thanks

Dan

I suppose that they have skipped a few steps. It is not a differential equation because there are no derivatives involved but to get from 2. to 3. subtract 8 from each side and simplify the right hand side of 2 by doing x-1.2x=-0.2x. This leaves you with an intermediate step between 2. and 3.:

0=-0.2x+0.4

if you add 0.2x to each side then you get step 3.
In general try to get all the xs on one side and try to simplify it. Hope this helps you

Thanks a lot, I've been studying how to do them and it's a lot clearer now.
Yes your reply was a help - thanks.