First, let's solve the expression inside the parentheses:

2 1/10:2-1,8

Convert 2 1/10 to an improper fraction:

2 1/10 = (2*10 + 1) / 10 = 21/10

Now, let's divide 21/10 by 2:

21/10 ÷ 2 = (21/10) * (1/2) = 21/20

Now, let's subtract 1,8 from 21/20:

21/20 - 1,8 = 21/20 - 1.8

Convert 1.8 to a fraction:

1.8 = 1 + 8/10 = 1 + 4/5 = 9/5

Now subtract:

21/20 - 9/5 = (215 - 920) / (20*5) = (105 - 180) / 100 = -75/100 = -3/4

Now, let's continue with the expression:

(-3/4) × 0.4 + 0.3

Multiply -3/4 by 0.4:

(-3/4) × 0.4 = -3/10

Finally, add 0.3:

-3/10 + 0.3 = -3/10 + 3/10 = 0

So, (2 1/10:2-1,8)×0,4+0,3 = 0.