Results 1 to 2 of 2

Math Help - finding expression and combining like terms

  1. #1
    Member
    Joined
    Dec 2006
    Posts
    93
    Awards
    1

    finding expression and combining like terms

    1. A triangle has sides 3x + 7, 4x , and 5x + 6. Find the expression
    that represents its perimeter.








    Combining like terms

    2. 7(4w-3)-25w
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Super Member Aryth's Avatar
    Joined
    Feb 2007
    From
    USA
    Posts
    651
    Thanks
    1
    Awards
    1
    Quote Originally Posted by Patience View Post
    1. A triangle has sides 3x + 7, 4x , and 5x + 6. Find the expression
    that represents its perimeter.








    Combining like terms

    2. 7(4w-3)-25w
    1. To find the perimeter of a triangle we use this equation:

    P = a + b + c

    Where a, b, and c are the sides of the triangle.

    So we just plug in the sides:

    P = (3x + 7) + (4x) + (5x + 6)

    Now we take out the parentheses:

    P = 3x + 7 + 4x + 5x + 6

    To combine like terms we look at each number and if they have certain things in common, we can add them.

    For the variables, any number that has a variable next to it can be added if the variables share the same power and the same variable, for example:

    2x + 5x = 7x

    They both share x^1 so they can be added, on the other hand:

    2x + 5x^2 = 2x + 5x^2

    They cannot be added because x and x^2 are not the same.

    Let's go back to the perimeter, we are going to go ahead and separate like terms:

    P = (3x + 4x + 5x) + (7 + 6)

    P = 12x + 13

    Because,

    3x + 4x + 5x = 12x

    Now for number 2:

    7(4w-3)-25w

    The like terms in here are 4w and -25w and 7 and -3. But the 7 is being distributed among th 4w-3 so let's look at it separately:

    7(4w - 3) = 7(4w) - 7(3) = 28w - 21

    The thing here is you can multiply ANY two terms regardless of if they are like terms, thus we can multiply 7 by 4w.

    Let's plug that back into the original problem:

    28w - 21 - 25w = (28w - 25w) - 21 = 3w -21

    I hope you understand it now. ^_^
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Combining Like Terms Calculator
    Posted in the Math Software Forum
    Replies: 1
    Last Post: March 22nd 2011, 11:25 AM
  2. Combining like terms?
    Posted in the Pre-Calculus Forum
    Replies: 2
    Last Post: September 27th 2009, 01:55 PM
  3. Replies: 1
    Last Post: October 2nd 2007, 07:15 PM
  4. combining like terms and solving equation.
    Posted in the Algebra Forum
    Replies: 4
    Last Post: February 27th 2007, 09:16 AM
  5. Simplifying - combining like terms
    Posted in the Algebra Forum
    Replies: 2
    Last Post: February 16th 2006, 06:13 AM

Search Tags


/mathhelpforum @mathhelpforum