1. Let's start with the first problem: Find the product of 3.5 and 2.8. 2. The formula for multiplication of decimals is the same as for whole numbers: multiply the numbers ignoring the decimal points, then place the decimal point in the product. 3. Multiply 35 by 28: $$35 \times 28 = 980$$ 4. Since 3.5 has 1 decimal place and 2.8 has 1 decimal place, the product must have $1 + 1 = 2$ decimal places. 5. Place the decimal point two places from the right in 980: $$9.80$$ 6. Therefore, the product is: $$3.5 \times 2.8 = 9.80$$ 7. The answer given as 7.5 is incorrect based on the calculation. 8. To summarize, the correct product is 9.80. This completes the solution for the first question.