# Help with a math formula? **URL:** \ **Category:** Questions\ **Created:** [July 27, 2019, 3:05am UTC](https://community.wolfram.com/t/help-with-a-math-formula/14525 "2019-07-27T03:05:51Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![digger1916](https://avatars.discourse-cdn.com/v4/letter/d/d6d6ee/32.png) [@digger1916](https://community.wolfram.com/u/digger1916)\ **Post date:** [July 27, 2019, 3:05am UTC](https://community.wolfram.com/t/help-with-a-math-formula/14525/1 "2019-07-27T03:05:51Z")
Hi Folks, apologies for what will be a dumb question, but if I wanted to find the value of ‘a’ in the formula: 960 = a(a-2)(a-3)(a-4) how would I go about that? Thanks a million to those who can help me! Mike ---
**Author:** ![rohitnamjoshi](https://avatars.discourse-cdn.com/v4/letter/r/f1d935/32.png) [@rohitnamjoshi](https://community.wolfram.com/u/rohitnamjoshi)\ **Post date:** [July 27, 2019, 3:56am UTC](https://community.wolfram.com/t/help-with-a-math-formula/14525/2 "2019-07-27T03:56:39Z")
Hi Mike, Using WL ``` Solve[960 == a (a - 2) (a - 3) (a - 4), a] // N (* {{a -> 8.}, {a -> -3.53019}, {a -> 2.2651 - 5.37232 I}, {a -> 2.2651 + 5.37232 I}} *) ``` ---
**Author:** ![digger1916](https://avatars.discourse-cdn.com/v4/letter/d/d6d6ee/32.png) [@digger1916](https://community.wolfram.com/u/digger1916)\ **Post date:** [July 27, 2019, 4:42am UTC](https://community.wolfram.com/t/help-with-a-math-formula/14525/3 "2019-07-27T04:42:12Z")
Hi Rohit, I greatly, greatly appreciate you taking the time to reply to my question. I’m still at a bit of a loss however… I can see that in the formula, a = 8… but I can’t see where the other figures come from, eg ({a → -3.53019… etc…), and when you say “Using WL”, I’m not sure what ‘WL’ is… I know this would be basic, and I am a little embarrassed, but this is eluding me… ☹☹ Mike ---
**Author:** ![jashonder](https://yyz1.discourse-cdn.com/wolfram/user_avatar/community.wolfram.com/jashonder/32/26540_2.png) [@jashonder](https://community.wolfram.com/u/jashonder)\ **Post date:** [July 27, 2019, 11:42am UTC](https://community.wolfram.com/t/help-with-a-math-formula/14525/4 "2019-07-27T11:42:34Z")
You could get the answer on [WolframAlpha](https://www.wolframalpha.com/input/?i=Solve%20960%20=%20a%28a-2%29%28a-3%29%28a-4%29). Click on the icon that says “Approximate Forms” and you will see the same answer Rohit gave. ---
**Author:** ![rohitnamjoshi](https://avatars.discourse-cdn.com/v4/letter/r/f1d935/32.png) [@rohitnamjoshi](https://community.wolfram.com/u/rohitnamjoshi)\ **Post date:** [July 28, 2019, 1:05am UTC](https://community.wolfram.com/t/help-with-a-math-formula/14525/5 "2019-07-28T01:05:46Z")
Mike, WL is a commonly used acronym for [Wolfram Language](https://www.wolfram.com/language/). The equation you are trying to find the roots of is a quartic polynomial. So there are four solutions some of which may be degenerate. If you expand and re-arrange a^4-9 a^3+26 a^2-24 a-960=0 ``` eq1 = Expand[a (a - 2) (a - 3) (a - 4)] - 960 == 0 (* -960 - 24 a + 26 a^2 - 9 a^3 + a^4 == 0 *) ``` Factoring yields one root, ` a = 8`. ``` Factor@eq1 (* (-8 + a) (120 + 18 a - a^2 + a^3) == 0 *) ``` The remaining cubic has three roots, one real `a = -3.53019` and two complex (which are conjugate) `a = 2.2651 - 5.37232 I` and `a = 2.2651 + 5.37232 I` You can visualize the real roots by plotting the function ``` Plot[Evaluate@First@eq1, {a, -5, 10}] ``` ![2336plot.png](https://global.discourse-cdn.com/wolfram/original/3X/0/d/0d34f7bf0fcd6436836d53437b2b3180fd30d8c6.png) If you are interested in just integer or real roots you can add a region specification to `Solve` ``` Solve[eq1, a \[Element] Integers] (* {{a -> 8}} *) Solve[eq1, a \[Element] Reals] // N (* {{a -> 8.}, {a -> -3.53019}} *) ``` Hope that helps. ---
**Author:** ![digger1916](https://avatars.discourse-cdn.com/v4/letter/d/d6d6ee/32.png) [@digger1916](https://community.wolfram.com/u/digger1916)\ **Post date:** [July 30, 2019, 6:09am UTC](https://community.wolfram.com/t/help-with-a-math-formula/14525/6 "2019-07-30T06:09:17Z")
Rohit… Thanks a million for that!!! It helped me enormously. Fabulous reply, and I am greatly indebted to you… thanks, and thanks, and thanks! 🙂 "-) regards, Mike ---
**Author:** ![digger1916](https://avatars.discourse-cdn.com/v4/letter/d/d6d6ee/32.png) [@digger1916](https://community.wolfram.com/u/digger1916)\ **Post date:** [July 30, 2019, 6:11am UTC](https://community.wolfram.com/t/help-with-a-math-formula/14525/7 "2019-07-30T06:11:00Z")
Thanks John… you folk on this forum as just so helpful. Wish there was a way I could return the favour. regards, Mike