- #1

- 1,041

- 3

## Homework Statement

Evaluate:

[tex]^{30}C_0 ^{30}C_{10}-^{30}C1 ^{30}C_11+...+^{30}C_{20} ^{30}C_{30}[/tex]

Again, I know this is some coeff of the product of some series, but I don't know how to find the series or the coeff.

I don't know how to go about it.