Write an algebraic expression to model the unknown number problem. Which stetements are true? Select all that apply. A. You can replace "a number" with a variable to represent an unknown value.

B. Quotient means the result of subtracting two numbers. Division involving a variable is represented as a fraction.

C. The correct expression is StartFraction 9 Over n EndFraction

D. The correct expression is StartFraction n Over 9 EndFraction

100 points bc why not -3-