Final answer:
The phrases translate mathematical operations into verbal language: 'product' is multiplication, 'difference' is subtraction, and 'quotient' is division, corresponding to the algebraic expressions with a number x.
Step-by-step explanation:
Completing the word phrase for each expression involves translating the algebraic operations into verbal language.
- The product of a number x and 8.1.
- The difference of 10 minus a number x and 9.
- The quotient of a number and 3.
- 1 minus the product of a number and another number.
Each phrase uses a keyword that signifies a specific mathematical operation: 'product' implies multiplication, and 'difference' and 'quotient' imply subtraction and division, respectively.