Question 1198624

Find the 7th term of the binomial (x+y)^9.

One of the following is the correct answer. Which one?

A) 84x^3 y^6
B) 36x^2 y^7
C) 210x^3 y^6
D) 84x^2 y^7
E) 36x^6 y^3
<pre>NO NEED to expand this binomial. I'd assume that one of the persons who responded and who did expand it would also expand it 
if it were to the 121<sup>st</sup> power: (x + y)<sup>121</sup>.

Use the formula for the specifcic term of a BINONIAL EXPANSION, which is: 
           {{{matrix(1,3, (a + b)^n, "=", " "[n]C[r - 1]*(a)^(n - r + 1)*(b)^(r - 1))}}}, where r = term number
{{{matrix(1,6, Term, 7, of, (x + y)^9, "=", " "[9]C[7 - 1]*(x)^(9 - 7 + 1)*(y)^(7 - 1))}}} ------ Substituting x for a, y for b, 9 for n, and 7 for r
                   {{{matrix(1,2, "=", " " [9]C[6]x^3y^6)}}}
                   {{{highlight_green(matrix(1,4, "=", highlight(84x^3y^6), "(CHOICE", "A)"))}}}</pre>