Math Help - Binomial Theorem

1. Binomial Theorem

14 a and b i cant get... please help

2. Originally Posted by Arbitur
14 a and b i cant get... please help
$(x+y)^{10}$
by binomial theorem
$
\left(\begin{array}{c}10\\0\end{array}\right)x^{10 }y^0
+
\left(\begin{array}{c}10\\1\end{array}\right)x^9y
+
\left(\begin{array}{c}10\\2\end{array}\right)x^8y^ 2
+$

$
+
\left(\begin{array}{c}10\\3\end{array}\right)x^7y^ 3
+
\left(\begin{array}{c}10\\4\end{array}\right)x^6y^ 4
+
\left(\begin{array}{c}10\\5\end{array}\right)x^5y^ 5
$

$
+
\left(\begin{array}{c}10\\6\end{array}\right)x^4y^ 6
+
\left(\begin{array}{c}10\\7\end{array}\right)x^3y^ 7
+
\left(\begin{array}{c}10\\8\end{array}\right)x^2y^ 8
$
$
+
\left(\begin{array}{c}10\\9\end{array}\right)xy^9
+
\left(\begin{array}{c}10\\10\end{array}\right)y^{1 0}
$

---------
When the combinatorics are evaluated we have,
$x^{10}+10x^9y+45x^8y^2+120x^7y^3+210x^6y^4+$ $252x^5y^5+210x^4y^6+120x^3y^7+45x^8y^2+10x^9y+y^{1 0}$