Results 1 to 2 of 2

Thread: [SOLVED] algebra word problems

  1. #1
    leesh2009
    Guest

    Question [SOLVED] algebra word problems

    The area of a triangle is 45 feet squared. If the base of the triangle is 4 less than half the height, what is the height and base of the trangle?
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Global Moderator

    Joined
    Nov 2005
    From
    New York City
    Posts
    10,616
    Thanks
    10
    Quote Originally Posted by leesh2009
    The area of a triangle is 45 feet squared. If the base of the triangle is 4 less than half the height, what is the height and base of the trangle?
    Let $\displaystyle x$ be the height,
    then $\displaystyle \frac{1}{2}x-4$ is the base.
    Since, area is 45 and you know that,
    $\displaystyle \frac{1}{2}\times (\mbox{height})(\mbox{base})=\mbox{Area}$
    Thus,
    $\displaystyle \frac{1}{2}x\left(\frac{1}{2}x-4\right)=45$
    Thus, open parantheses,
    $\displaystyle \frac{1}{4}x^2-2x=45$
    Now, multiply this by 4 to get,
    $\displaystyle x^2-8x=180$
    Thus,
    $\displaystyle x^2-8x-180=0$
    Thus,
    $\displaystyle (x+10)(x-18)=0$
    Thus,
    $\displaystyle x=-10,18$ reject the negative.
    Thus, $\displaystyle x=18$
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Help with some algebra 2 word problems.
    Posted in the Algebra Forum
    Replies: 1
    Last Post: Mar 29th 2011, 01:20 AM
  2. Word Problems - Algebra.
    Posted in the Algebra Forum
    Replies: 2
    Last Post: Dec 11th 2009, 02:48 PM
  3. algebra word problems
    Posted in the Algebra Forum
    Replies: 2
    Last Post: Oct 11th 2009, 05:12 AM
  4. Word Problems (algebra)
    Posted in the Algebra Forum
    Replies: 1
    Last Post: Dec 14th 2008, 10:04 PM
  5. algebra word problems
    Posted in the Pre-Calculus Forum
    Replies: 3
    Last Post: Jul 26th 2008, 05:35 PM

Search Tags


/mathhelpforum @mathhelpforum