(21,7 : 6,2 - 11: 4,4)*3/4

Let's break down the expression step by step and solve it:

(21,7 : 6,2 - 11: 4,4) * 3/4

The first step is to perform the division operations within the parentheses:

21,7 : 6,2 = 3,5 (since 21.7 divided by 6.2 equals 3.5) 11 : 4,4 = 2,5 (since 11 divided by 4.4 equals 2.5)

Now let's plug these values back into the original expression:

(3,5 - 2,5) * 3/4

Now, let's perform the subtraction within the parentheses:

3,5 - 2,5 = 1,0 (since 3.5 minus 2.5 equals 1.0)

Now we are left with:

1,0 * 3/4

Convert mixed numbers to improper fractions to solve this:

1,0 is just 1.

So the final calculation is:

1 * 3/4

Multiplying 1 by 3/4 is straightforward:

1 * (3/4) = 3/4

So the final answer is 3/4 or 0.75 (convert the fraction to decimal).