To solve this expression, we need to follow the order of operations (PEMDAS).

First, let's simplify each fraction:

3/4 = 3/4
5/6 = 5/6
5/2 = 2.5
2/5 = 0.4
1/10 = 0.1

Now we can plug in these values:

3/4 + 5/6 + 2.5 x 0.4 - 0.1 ÷ 10/9

Next, let's perform the multiplication and division operations:

3/4 + 5/6 + 1.0 - 0.01 ÷ 10/9
3/4 + 5/6 + 1.0 - 0.01 x 9/10
3/4 + 5/6 + 1.0 - 0.009
0.75 + 0.83 + 1.0 - 0.009
2.58 - 0.009

Finally, let's subtract:

2.58 - 0.009 = 2.571

Therefore, the result of 3/4 + 5/6 + 5/2 x 2/5 - 1 ÷ 10/9 is 2.571.