7 7/20-4,75+3 4/5

To solve the expression \( 7 \frac{7}{20} - 4.75 + 3 \frac{4}{5} \), we can first convert all numbers to improper fractions or decimals for easier calculations.

1. Convert \( 7 \frac{7}{20} \) to an improper fraction: \[ 7 \frac{7}{20} = \frac{7 \times 20 + 7}{20} = \frac{140 + 7}{20} = \frac{147}{20} \]

2. Convert \( 4.75 \) to a fraction: \[ 4.75 = \frac{475}{100} = \frac{19}{4} \text{ (by simplifying)} \]

3. Convert \( 3 \frac{4}{5} \) to an improper fraction: \[ 3 \frac{4}{5} = \frac{3 \times 5 + 4}{5} = \frac{15 + 4}{5} = \frac{19}{5} \]

Now we rewrite the expression using these fractions: \[ \frac{147}{20} - \frac{19}{4} + \frac{19}{5} \]

Next, we need to find a common denominator for \( 20 \), \( 4 \), and \( 5 \). The least common multiple (LCM) of \( 20 \), \( 4 \), and \( 5 \) is \( 20 \).

Now, we will rewrite each fraction with a denominator of \( 20 \):

• \( \frac{147}{20} \) remains \( \frac{147}{20} \)

• For \( \frac{19}{4} \): \[ \frac{19}{4} = \frac{19 \times 5}{4 \times 5} = \frac{95}{20} \]

• For \( \frac{19}{5} \): \[ \frac{19}{5} = \frac{19 \times 4}{5 \times 4} = \frac{76}{20} \]

Now substituting these back into the expression: \[ \frac{147}{20} - \frac{95}{20} + \frac{76}{20} \]

Combine the fractions: \[ \frac{147 - 95 + 76}{20} = \frac{28}{20} \]

Now simplify \( \frac{28}{20} \): \[ \frac{28 \div 4}{20 \div 4} = \frac{7}{5} = 1 \frac{2}{5} \]

So, the final answer is: \[ 1 \frac{2}{5} \] or \( \frac{7}{5} \) as an improper fraction.