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How to Isolate a Variable in the Denominator

Many algebraic equations involve in finding the value of an unknown variable. To find the value of the variable, some manipulation is needed to isolate the intended variable. A variable is usually isolated using the basic mathematical functions of adding, subtracting, multiplying and dividing. In mathematical terms, a variable is an unknown term which is denoted using a letter. It is important to remember that the variable is expressed as a positive letter to obtain the proper answer. Isolating a variable from the denominator will use a mixture of the basic math functions to complete.

Paper
Pencil

Instructions

- 1
  Write down the equation you are solving. The equation "2=(2x3)/(a+5)" will illustrate how to isolate a variable in the denominator.
- 2
  Multiply both sides of the equation by the terms in the denominator, the terms cancel each other on the right hand side. After this step the example should be: (a+5)2=(2x3).
- 3
  Multiply the terms in parenthesis with the 2 on the left hand side of the equation. Multiply the terms in the parenthesis on the right hand side as well. The result should now be: 2a+10=6.
- 4
  Subtract the 10 from both sides of the equation. The equation should be: 2a=6-10.
- 5
  Perform the subtraction on the right hand side of the equation to get 2a=-4.
- 6
  Divide the two on both sides of the equation to isolate the variable. The result is now: a=-4/2. When the math is carried out the answer is: a=-2.

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