Formula for finding a particular term in expansion of (a + b)n is: Ex.: Find the 4th term in expansion of (a + b)9: This is the 4th term, so value of r (b’s exponent) is 4 – 1 = 3. This means the exponent for a is 9 – 3, or 6. So, we have the variables of the 4th term: a6b3. Coefficient is:
