Howdy /sci/, first time poster
Working on something for work (in my own time as a bit of a project) and I'm stuck with an equation I need to reverse for working out wages.
The formulas we're provided with will calculate tax on a gross amount, which is withheld and the employees get paid the net amount after tax. I want to work it backwards.
We're given the following formula
>y=ax-b
>Where y=tax
>a=gross
>x= Coefficient x
>b= Coefficient b
>n= net
I'm bloody hopeless at math and even worse with algebra so the closest I've come is
>n=g-(gx-b)
But stuffed if I know how to solve it.
Pic is my silly table.
Bump
>>7654230
Question is not clear. You're given
Gross = Net - Tax
Tax = Gross * X - B
And you want to solve for what as a function of what?
>>7654253
In a real situation, we are only given the Net amount.
Given that I know what X and B are for that particular figure, I want to be able to figure out the tax on Net.
>>7654259
What is tax on net, isn't the tax on the gross amount?
>>7654269
Sorry yeah. I'm braindead from trying to figure this out.
The normal way to figure it out would be
>Gross -> Tax -> Net (being Gross - Tax)
I want to follow this backwards, being
>Net -> Tax -> Gross
Reason I'm trying to do this is nearly 100% of all small clients will draw a cash wage for their employees and tell us to work out the tax when they bring their books up, which takes ages as we need to work backwards from the tax rate tables (provided by our govt)
I was hoping I could automate this in a spreadsheet to make it a little quicker
>>7654259
Tax = Gross * X - B
Since Gross = Net - Tax
Tax = (Net - Tax) * X - B
Tax = Net * X - Tax * X - B
Tax + Tax * X = Net * X - B
Tax (1+X) = Net * X - B
So
Tax = (Net * X - B)/(1+X)
and
Gross = Net - (Net * X - B)/(1+X)
>>7654293
The tax formula doesn't seem to work...I'm getting $53.265 instead of $82.8358?
Thanks for helping out, by the way. So glad I'm finally getting somewhere with this project (been working on it for months!)
>>7654312
My mistake, replace 1+X with 1-X since Gross = Net + Tax, not Net - Tax
>>7654323
That works!
Thanks man. I owe you pic related
>>7654340
You're welcome anon