Results 1 to 2 of 2

Thread: A tricky linear equation

  1. #1
    Junior Member
    Joined
    Sep 2009
    From
    Vadodara,Gujarat,India
    Posts
    33

    Post A tricky linear equation

    If a and b are natural numbers and a + b + ab = 948 then find the value of a + b
    Please Help!
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Super Member

    Joined
    May 2006
    From
    Lexington, MA (USA)
    Posts
    12,028
    Thanks
    848
    Hello, anshulbshah!

    If $\displaystyle a$ and $\displaystyle b$ are natural numbers and $\displaystyle a + b + ab \:=\: 948$

    then find the value of $\displaystyle a + b$.

    Add 1 to both sides: .$\displaystyle ab + a + b + 1 \:=\:949$

    Factor both sides: .$\displaystyle (a+1)(b+1) \:=\:13\cdot73$

    One solution is: .$\displaystyle \begin{array}{ccccc} a+1 \:=\:13 & \Rightarrow & a \:=\:12 \\ b+1 \:=\:73 & \Rightarrow & b \:=\:72 \end{array}$


    Therefore: .$\displaystyle a + b \;=\;12 + 72 \;=\;\boxed{84}$

    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. tricky linear algebra proof
    Posted in the Advanced Algebra Forum
    Replies: 9
    Last Post: Apr 6th 2011, 11:02 PM
  2. tricky little first order linear DE
    Posted in the Differential Equations Forum
    Replies: 4
    Last Post: Nov 27th 2010, 08:29 AM
  3. Tricky sin equation
    Posted in the Trigonometry Forum
    Replies: 5
    Last Post: Apr 24th 2010, 10:44 PM
  4. Replies: 6
    Last Post: Jul 14th 2008, 04:00 AM
  5. This is tricky..Linear algebra again
    Posted in the Advanced Algebra Forum
    Replies: 1
    Last Post: Apr 20th 2008, 04:25 AM

Search tags for this page

Search Tags


/mathhelpforum @mathhelpforum