5th term from the end in the expansion of x23−3x28is:

As number of terms in the binomial expansion of (x+a)n is (n+1), the rth term from the end is ((n+1)+(−1)(r−1))th=(n+2−r) th term from the beginning.Here n=8, r=5, thus, 5th term from the end is (8+2-5)th5thterm from the beginning, and it is given byt5=8C4x234−3x28−4=8C4=70