Which algebraic expression is a difference with two terms?
A.6(x + 5)
B.6x – 9
C.6 + x – 9
D.9x ÷ 6

In algebraic expression two terms are in difference in one term is subtracted from the other term.
In expression 6x - 9, term 9 is substracted from term 6x. So expression 6x - 9 is a difference with two terms.
So answer is 6x - 9.