6 3/4-2 5/6-1 3/8=

To subtract mixed fractions like 6 3/4, 2 5/6, and 1 3/8, we need to convert them to improper fractions first.

Step 1: Convert 6 3/4 to an improper fraction. 6 3/4 = (6 * 4 + 3)/4 = 27/4

Step 2: Convert 2 5/6 to an improper fraction. 2 5/6 = (2 * 6 + 5)/6 = 17/6

Step 3: Convert 1 3/8 to an improper fraction. 1 3/8 = (1 * 8 + 3)/8 = 11/8

Now we can perform the subtraction:

27/4 - 17/6 - 11/8

To subtract fractions, we need a common denominator. The least common multiple (LCM) of 4, 6, and 8 is 24, so we will use 24 as the common denominator.

Step 4: Convert each fraction to have a common denominator of 24.

27/4 * 6/6 = 162/24 17/6 * 4/4 = 68/24 11/8 * 3/3 = 33/24

Now we can subtract the fractions:

162/24 - 68/24 - 33/24

Step 5: Subtract the numerators:

162 - 68 - 33 = 61

The denominator remains the same: 24

So, the result is 61/24.