1. The problem is to interpret the expression "8,3X0,72" which appears to be a number with commas and an uppercase X. 2. Assuming the commas are decimal separators and the X represents multiplication, rewrite the expression as $8.3 \times 0.72$. 3. Use the multiplication formula for decimals: multiply the numbers ignoring the decimal points, then place the decimal point in the product. 4. Calculate $83 \times 72 = 5976$. 5. Since $8.3$ has one decimal place and $0.72$ has two decimal places, the product must have $1 + 2 = 3$ decimal places. 6. Place the decimal point three places from the right in $5976$ to get $5.976$. 7. Therefore, $8.3 \times 0.72 = 5.976$.