Blog Assignment

Adding and Subtracting Positive and Negative Fractions

Okay, let's say this is the question:
(-1 1/3) - (2 1/4)

What do you do? Well, first you should put the mixed numbers into fractions. This is how you do that:

-1 1/3 = 4/3

2 1/4 = 9/4

Now the equation should look like this:
(- 4/3) - (9/4)

Now the denominators need to be the same. To get them to be the same, you have to find a common denominator. The easiest way to do that is to multiply the 2 denominators:
3 x 4= 12

So to make the fraction the same amount, just with different denominators, we have to multiply the numerator and the denominator by the same number, like this:

4 x 4= 16
3 x 4= 12 so 4/3 = 16/12

9 x 3= 27
4 x 3= 12 so 9/4 = 27/12


Now, because its a subtraction question, you have to change some signs. You have to change the subtraction sign to an addition sign and the sign of the second number to its opposite. It should now look like this:
(-16/12) + (-27/12)

Now just add them together, and you should get this answer:
-42/12 which can then be made into a mixed number, which is:
-3 6/12 which can be reduced to:
-3 1/2

ITS THAT EASY !!