# Prove that for n>=2,2 cdot (begin{matrix}{n}{2}end{matrix})+(begin{matrix}{n}{1}end{matrix})=n^2

Prove that for $n\ge 2,2\cdot \left(\begin{array}{c}n\\ 2\end{array}\right)+\left(\begin{array}{c}n\\ 1\end{array}\right)={n}^{2}$

You can still ask an expert for help

• Questions are typically answered in as fast as 30 minutes

Solve your problem for the price of one coffee

• Math expert for every subject
• Pay only if we can solve it

Ayesha Gomez
Prove that for
$n\ge 2,2\cdot \left(\begin{array}{c}n\\ 2\end{array}\right)+\left(\begin{array}{c}n\\ 1\end{array}\right)={n}^{2}$
Step 1. Definitions
Definition combination
$nCr=\left(\begin{array}{c}n\\ r\end{array}\right)=\frac{n!}{r!\left(n-r\right)!}$
with $n!=n×\left(n-1\right)×\cdots ×2×1$.
Pascals