Answer:
7xy
General Formulas and Concepts:
Pre-Algebra
Order of Operations: BPEMDAS 
- Brackets 
- Parenthesis 
- Exponents 
- Multiplication 
- Division 
- Addition 
- Subtraction 
Algebra I
- Terms/Coefficients/Degrees
Explanation:
Step 1: Define
"Product of x and 7y"
Step 2: Translate
"Product" is multiplication
"x" is x
"7y" is 7y
Step 3: Write
- Multiplication: x · 7y
- Simplify: 7xy