How do you expand #(m+n)^5#?

1 Answer
Dec 7, 2016

#1m^5+5m^4n+10m^3n^2+10m^2n^3+5mn^4+1n^5#

Explanation:

If you know the 5th row of Pascal's Triangle: 1, 5, 10, 10, 5, 1,
those are the coefficients of each term.

Start the powers of "m" at the highest, 5, and work your way down.
Repeat with powers of "n" from the opposite end.
#1m^5+5m^4n+10m^3n^2+10m^2n^3+5mn^4+1n^5#

Notice that each term has powers of "m" and "n" that add up to 5!