# Solving equations in Excel based examines

**URL:** <https://community.goactuary.com/t/solving-equations-in-excel-based-examines/2446>\
**Category:** CAS Exam 9\
**Created:** [March 28, 2021, 10:46pm UTC](https://community.goactuary.com/t/solving-equations-in-excel-based-examines/2446 "2021-03-28T22:46:29Z")\
**Posts on this page:** 8\
**Page:** 1

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**Author:** ![godoodim](https://community.goactuary.com/user_avatar/community.goactuary.com/godoodim/32/4309_2.png) [@godoodim](https://community.goactuary.com/u/godoodim)\
**Post date:** [March 28, 2021, 10:46pm UTC](https://community.goactuary.com/t/solving-equations-in-excel-based-examines/2446/1 "2021-03-28T22:46:29Z")

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I think many of us find Excel based exams are great in alleviating math calculations in general, however, it is a bit cumbersome if we have to solve math equations in the Excel environment. Just wondering if there is any good way (or best practice) to handle equation solving in Excel.

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**Author:** ![skysn93](https://community.goactuary.com/letter_avatar_proxy/v4/letter/s/13edae/32.png) [@skysn93](https://community.goactuary.com/u/skysn93)\
**Post date:** [March 29, 2021, 1:26pm UTC](https://community.goactuary.com/t/solving-equations-in-excel-based-examines/2446/2 "2021-03-29T13:26:10Z")

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I’m using RF and what they’ve been doing in their practice problems is setting a cell equal to the unknown variable with an initial guess, then do the problem normally, then adjust the unknown variable until the question conditions are met. I haven’t minded that method too much because, for me, it usually is faster than trying to convert solving an algebraic equation into Excel.

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**Author:** ![CuriousGeorge](https://community.goactuary.com/user_avatar/community.goactuary.com/curiousgeorge/32/28457_2.png) [@CuriousGeorge](https://community.goactuary.com/u/CuriousGeorge)\
**Post date:** [March 29, 2021, 1:30pm UTC](https://community.goactuary.com/t/solving-equations-in-excel-based-examines/2446/3 "2021-03-29T13:30:22Z")

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Another method is to put each number and each set of non-numbers in its own cell:

A5 B5 C5 D5 E5  
3.5 “(x-” 12 “)=” 17  
It takes a little longer to type out that way, but it’s very readable, and you can do straight references to combine numerical pieces as you solve the equation.

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**Author:** ![godoodim](https://community.goactuary.com/user_avatar/community.goactuary.com/godoodim/32/4309_2.png) [@godoodim](https://community.goactuary.com/u/godoodim)\
**Post date:** [April 3, 2021, 10:14pm UTC](https://community.goactuary.com/t/solving-equations-in-excel-based-examines/2446/4 "2021-04-03T22:14:08Z")

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I think that’s a great idea. How would you solve the unknown after that? Or do you mind sharing which RF problem had this example? Thanks!

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**Author:** ![godoodim](https://community.goactuary.com/user_avatar/community.goactuary.com/godoodim/32/4309_2.png) [@godoodim](https://community.goactuary.com/u/godoodim)\
**Post date:** [April 3, 2021, 10:14pm UTC](https://community.goactuary.com/t/solving-equations-in-excel-based-examines/2446/5 "2021-04-03T22:14:48Z")

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Thanks for sharing. I think this is a good idea too.

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**Author:** ![CuriousGeorge](https://community.goactuary.com/user_avatar/community.goactuary.com/curiousgeorge/32/28457_2.png) [@CuriousGeorge](https://community.goactuary.com/u/CuriousGeorge)\
**Post date:** [April 4, 2021, 1:35pm UTC](https://community.goactuary.com/t/solving-equations-in-excel-based-examines/2446/6 "2021-04-04T13:35:22Z")

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It looks like it was Crystal Clear that does this. Here is a snippet of solving BKM spot rate formulas:

 ![formulaexample](https://community.goactuary.com/uploads/default/original/2X/5/5521664ab2d09d690871c04c4d385c37df5a77fe.jpeg)  
It’s very nice for following their solutions, I’m less convinced it is helpful for exam conditions. I’ve been doing it maybe 1/4 of the time.

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**Author:** ![exekias](https://community.goactuary.com/user_avatar/community.goactuary.com/exekias/32/138_2.png) [@exekias](https://community.goactuary.com/u/exekias)\
**Post date:** [May 4, 2021, 1:59am UTC](https://community.goactuary.com/t/solving-equations-in-excel-based-examines/2446/7 "2021-05-04T01:59:57Z")

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That is what I have been doing as well. A useful extension is that for linear problems you can use the FORECAST function. Just get two seed values and extrapolate to get the answer. Most exam problems that expect you to solve for an unknown algebraically are linear, so this method is almost always applicable.

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**Author:** ![SinisterRobert](https://community.goactuary.com/letter_avatar_proxy/v4/letter/s/ce73a5/32.png) [@SinisterRobert](https://community.goactuary.com/u/SinisterRobert)\
**Post date:** [May 4, 2021, 5:44pm UTC](https://community.goactuary.com/t/solving-equations-in-excel-based-examines/2446/8 "2021-05-04T17:44:37Z")

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Even if the solution function isn’t linear, the linear function will probably get you really close still, and you can apply it again with your new solution point and one of your seed points iteratively until you get the accuracy you want.
