Question

How do you expand `(p+q)^5`?

Answer 1

`p^5+5p^4q+10p^3q^2+10p^2q^3+5pq^4+q^5`

Explanation:

Write out Pascal's triangle to the the fifth line or memorize the first few lines:
1
1 1
1 2 1
1 3 3 1
1 4 6 4 1
1 5 10 10 5 1

Then write out the `p`'s and `q`'s with the powers going in opposite directions. Make sure that the index of `p` plus the index of `q` in each term add up to `5`.