Melissa P. answered • 10/16/14

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First you need to find a common denominator for the 3 fractions given:

5/6

1/2

7/8

Ask yourself, what number is divisible by 6, 2, and 8?

The answer is 24, because

6 x 4= 24

2 x 12= 24

8 x 3= 24

After you find the common denominator, multiply the numerators by the same number you multiplied the denominators with to get your common denominator:

5 x 4= 20

1 x 12= 12

7 x 3 = 21

Your new equation should be rewritten as follows:

20/24x - 12/24 = 21/24

Because all the denominators are 24, you can omit them:

20x - 12 = 21

Solve for x by isolating it -- get rid of the 12 by adding 12 on both sides of the equal sign so that they cancel each other out:

20x - 12 = 21

+ 12 +12

____________

20x = 33

To isolate x from 20, divide by 20 on both sides of the equal sign:

20x 33

____ = ____

20 20

20x/20= 1x or just x, therefore --

x = 33/20, however 33/20 can be simplified by writing it as a mixed number:

1) Divide -- how many times does 20 go into 33?

1 time, with a remainder of 13.

2) Rewrite it with the whole number (number of times denominator goes into numerator evenly) = 1

Take the remainder and make it the numerator = 13

Take the denominator of the improper fraction and make it the denominator of the mixed number = 20

Your answer as a mixed number is x = 1 ¹³⁄²°

Your answer as an improper fraction is x = 33/20