# How do I use Pascal's triangle to expand #(3a + b)^4#?

##### 1 Answer

Jul 3, 2015

#### Answer:

Combine a row of Pascal's triangle with a list of powers of

#### Explanation:

Write out the 5th row of Pascal's triangle as a sequence:

Write out powers of

Multiply the two sequences together to get the sequence:

These are the coefficients of the expansion: