Binomial theorem

Question

Find the coefficient of the indicated term in each expansion

(2n-3m)^4 , 4th term

Answer 1

In the 4th term, the first expression has exponent 1 and the 2nd expression has exponent 3

so (4 choose 1) (2n)^1 (-3m)^3 =

4 (2n)(-27m^3) = -216 n m^3