You want to place a towel bar that is 10 1⁄4 inches long in the center of a door that is 26 1⁄3 inches wide. how far should you place the bar from each edge of the door? (write the answer as a mixed number.)

The bar should be 8 1/24 from the each edge of the door.

We need to subtract 10 1/4 from 26 1/3 to get the fraction of the space not covered by the towel bar. 
We also need to divide the difference by 2 because we placed the towel bar in the center of the door.

1st we need to convert the mixed fractions into fractions to perform subtraction.
26 1/3 = ((26*3)+1)/3 = 79/3
10 1/4 = ((10*4)+1)/4 = 41/4

Steps in Subtracting Fractions
Step 1. Make sure the denominator is the same. 3 and 4 are the denominators, they are not the same but they are factor of 12. So,
79/3 must be multiplied by 4 = 79 * 4 / 3 * 4 = 316 / 12
41/4 must be multiplied by 3 = 41 * 3 / 4 * 3 = 123 / 12

Step 2. Subtract the numerators and place them above the common denominator
316/12 - 123/12 = 316 - 123 / 12 = 193 / 12

Before we can simplify the fraction, we must divide it by two to get the measurement of each edge of the door.

Steps in dividing fractions.
Step 1. Get the reciprocal of the 2nd fraction.
1st fraction : 193 / 12
2nd fraction : 2 /1  ⇒ reciprocal 1/2

Step 2. Multiply the 1st fraction to the reciprocal of the 2nd fraction
193 / 12 * 1/2 = 193 * 1 / 12 * 2 = 193 / 24

Step 3. Simplify the fraction.
193 / 24 = 8 1/24

One that half its volume