Directions: Encircle the letter of the correct answer. 1. What is a variable? A. Any letter or symbol that represents a number B. Any number or symbol that represents a letter C. Any expressions that mbines numbers D. A fixed value that does not change 2. A mathematical phrase that uses variables, numerals, and operation symbols is called A. numerical expression B. constant C. variable D. algebraic expression 3. A mathematical sentence with an equal sign is called A. numerical expression B. variable C. algebraic expression D. equation 4. Translate this phrase into an algebraic expression If nine is added to the difference of a number and nineteen, the sum is ninety A b - 19 + 9 = 90 B. B. b + 19-9-90 C. C. b - 19 + 9 = 90 D. D. b x 19 + 990​