Question

Use Pascal’s Triangle to determine the fifth term of the expansion of (x + 3)7

Answer 1

2835x^5.

Explanation:

By Binomial Theorem, T(r+1) = nCr * a^(r+1) * b^r.

Term 5 = 7C4 * x^5 * 3^4

= 35 * x^5 * 3^4

= 2835x^5.