Forum Discussion
Solve for x on both sides of an equation
Here is my formula "on paper": x = ((70/100)*x) +14
I don't know how to set up a way for Excel to return a value for x.
Through trial and error, the answer to the above formula is approximately 46, which is close enough for my needs. 70/100*46 = 32.2 ; 32.2 + 14 = 46.2
The formula could also be
y = ((70/100)*x) + 14
where y and x are close in value. Ideally, y = x.
Since x could be any number between, say, 5 and 500, would I do something with Excel's "lookup" function?
Mark, I didn't catch.
Your formula "on paper", if transform
x=14/0.3
which is roundly 46.67
Mark, I didn't catch.
Your formula "on paper", if transform
x=14/0.3
which is roundly 46.67
- That is exactly correct. You've solved the riddle for me. It never occurred to me to use 100-70. Now I can type in Excel:
=14/((100-70)/100) and get 46.67.
Replacing the 14 and the 70 with 10 and 90, I get an answer of 100.
So, now I can plug in any values, with 14 = Errors and 70 = Percentage Correct: the formula is then
=Errors/((100-Percentage)/100)
and I can assign a cell to Errors and a different cell to Percentage, such as E1 and P1:
=E1/((100-P1)/100)
I am so grateful for your mathematical wisdom. Thanks!!
