CPM Homework Help : CCA2 Problem 10-157

Use the pattern for $(a + b)^4$ to expand $(3x + 1)^4$ .

Hint:

Recall Pascal's Triangle and the expanded form of $(a + b)^4$ .

More Help:

Substitute $3x$ for $a$ and $1$ for $b$ .

Answer:

$81x^4 + 108x^3 + 54x^2 + 12x + 1$