Reversing a Formula

[Volcano]

Hi,
My apologies in advance if this is a dumb question.
I begin with a figure of, say, $500,000 (eg Cell E8).
I take $70,000 at a rate of 2%.
The balance is rated at 4% and added to the above.
My formula now looks like this......=(70000*2%)+(E8-70000)*4%
The result is $18,600.
Using the above percentages, and if I know the value of $18,600 in advance, how can I adjust my formula to show a value at E8.
Hope this makes sense.
Cheers
Volcano

 

[jproffer]

((18,600 - (70,000*0.02))/0.04) + 70,000 = E8

....I think

 

[StephenCrump]

Assuming $18,600 in E9:

=25*(E9+MIN(E9,1400))

 

[Volcano]

Hi, Guys,
Wow, that was quick.
Thank you both for your answers....I really do appreciate your help, and I now don't have to pull out any more hair.
With kind regards
Volcano

 

[Fazza]

Goal Seek

or maybe you want goal seek - maybe simplest to explain by example

put 0 in cell E8
ALT-T-G
set cell : the one with the result, in this case 18,600
to value : 18600
by changing : cell E8
OK