True or false the coefficient of (x^(k)) (y^(n-k)) in the expansion of (x+y)^n equals (n choose k)

This is under the binomial theorem. A binomial theorem is an equation that predicts the sequence when a binomial is raised to certain power. The general form of the equation is (a+b)^n. The equation for the binomial theorem would be

nCk a^(n-k) b^k, where k is the kth term of the expanded form, n is the nth power. The coefficient of the term in the binomial expansion is nCk or n!/k!(n-k)!.

What class is this? i have no idea and i'm not going to give you the wrong answer. do you have a graph that goes with all the questions