Step 13: The coefficient of x^4 in the expansion is 2160.
Binomial Theorem – The Binomial Theorem is used to expand expressions of the form (a + b)^n, where the coefficients can be determined using combinations.
Combinations – Understanding how to calculate combinations (nCr) is essential for determining the coefficients in the expansion.
Negative Exponents – Recognizing how to handle negative numbers in the expansion, particularly when raised to an even power.