Advertisement
Help Keep Boards Alive. Support us by going ad free today. See here: https://subscriptions.boards.ie/.
If we do not hit our goal we will be forced to close the site.

Current status: https://keepboardsalive.com/

Annual subs are best for most impact. If you are still undecided on going Ad Free - you can also donate using the Paypal Donate option. All contribution helps. Thank you.
https://www.boards.ie/group/1878-subscribers-forum

Private Group for paid up members of Boards.ie. Join the club.

Maths Factorisation Question

  • 01-11-2015 05:39PM
    #1
    randomlad727
    Registered Users, Registered Users 2 Posts: 29 ✭


    Hello. Just wondering if anybody could help me factorise the equation: a^2 +2ab+10b^2=0 (the ^ meaning to the power of)

    Thanks in advance for any help.


Comments

  • #2
    PinkLemonade
    Closed Accounts Posts: 768 ✭✭✭PinkLemonade


    Are you sure on the signs?


  • #3
    randomlad727
    Registered Users, Registered Users 2 Posts: 29 ✭randomlad727


    Actually coming to think of it I may be going wrong earlier in the question. It is an abstract inequality question.
    The equation starts off as : a^2 > -2b(a+5b) . I assumed you would multiply out the brackets and then bring everything to one side but maybe this is where I am going wrong. (> supposed to mean greater than or equal too but I dont know how to get the full sign on the keyboard)


  • #4
    skippy1977
    Registered Users, Registered Users 2 Posts: 284 ✭✭skippy1977


    You were on the right track. Trick is to split the 10 up into 9+1...that way you can complete a square with the other terms (which must be positive, or 0) and the 9b^2 is also positive (or 0)

    Inequality.png


  • #5
    randomlad727
    Registered Users, Registered Users 2 Posts: 29 ✭randomlad727


    Great! Thank you for your help! Much appreciated! :)


Advertisement