29/25 + 5/21 - 4/23 +0,51 +16/21

To add these fractions, we need to find a common denominator. In this case, the common denominator is 105.

(29/25) + (5/21) - (4/23) + (0.51) + (16/21)

First, convert the mixed number 0.51 to a fraction:

0.51 = 51/100

Now, rewrite the expression with a common denominator of 105:

(29/25) + (5/21) - (4/23) + (51/100) + (16/21)

Now, convert each fraction to have a denominator of 105:

(29/25) = (29/25) * (4/4) = 116/100
(5/21) = (5/21) * (5/5) = 25/105
(4/23) = (4/23) * (4/4) = 16/92
(51/100) = 51/100
(16/21) = (16/21) * (5/5) = 80/105

Now, rewrite the expression with the common denominator of 105:

(116/100) + (25/105) - (16/92) + (51/100) + (80/105)

Now, add the fractions:

(116/100) + (25/105) - (16/92) + (51/100) + (80/105) = 1.16 + 0.2381 - 0.1739 + 0.51 + 0.7619 = 2.4911

Therefore, the result of the expression is 2.4911.