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What's the Value of x?


Date: 07/25/97 at 02:49:24
From: lemuel joshah m. mariano
Subject: Equation

I am trying to find out the value of "x":

2x = x+18+27 and 3x = 2x+7+9


Date: 07/25/97 at 12:28:26
From: Doctor Rob
Subject: Re: Equation

To solve linear equations in one variable where no powers of variables 
appear, follow these steps:

  1. Move all terms involving the variable to one side of the
     equation, and all other terms to the other.
  2. Combine like terms.
  3. Divide the equation by the coefficient of the variable.

In the first case, we start with

  2*x = x + 18 + 27

We want to move the "x" term to the left side, which we do by adding
its negative to both sides:

  2*x - x = 18 + 27

Now we combine like terms:

  (2 - 1)*x = 18 + 27
        1*x = 45

Lastly we divide by the coefficient of x, in this case, 1.

  x = 45/1
  x = 45

You do the second one, using the same three steps.

-Doctor Rob,  The Math Forum
 Check out our web site!  http://mathforum.org/dr.math/   
    
Associated Topics:
Middle School Algebra

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