To solve this expression, we need to simplify each term separately and then perform the operations.

First, let's simplify each term:

3/7 × 26 1/3:
To multiply a whole number by a fraction, we can convert the whole number to a fraction by placing it over 1. So, 26 can be written as 26/1.
Now, we multiply the numerators (3 × 26) and the denominators (7 × 1):
(3 × 26) / (7 × 1) = 78/7

Next, let's simplify the mixed number 1/3:
To convert a mixed number to an improper fraction, we multiply the whole number by the denominator and add the numerator. Then, we place the result over the denominator.
(1 × 3 + 1) / 3 = 4/3

Now, we have:
78/7 - 4/3

Next, let's simplify the second term:

3/7 × 19 1/3:
Again, we convert the whole number to a fraction: 19/1.
Multiplying the numerators (3 × 19) and the denominators (7 × 1):
(3 × 19) / (7 × 1) = 57/7

Simplifying the mixed number 1/3:
(1 × 3 + 1) / 3 = 4/3

Now, we have:
57/7 - 4/3

Finally, let's simplify the last term:

2/5

Now, we have:
57/7 - 4/3 - 2/5

To subtract fractions, we need a common denominator. In this case, the least common denominator (LCD) is 7 × 3 × 5 = 105.

Converting each fraction to have a denominator of 105:

(57/7) × (15/15) = 855/105
(4/3) × (35/35) = 140/105
(2/5) × (21/21) = 42/105

Now, we have:
855/105 - 140/105 - 42/105

Combining the numerators:
(855 - 140 - 42) / 105 = 673/105

Therefore, the simplified expression is 673/105.