Answer:
5th term is 35a^4b^3
Step-by-step explanation:
We need to find the 5th term in binomial expansion (a+b)^7
The binomial theorem is:
[tex](x+y)^n = \sum_{n=0}^{k} {n\choose k}x^ky^{n-k}[/tex]
We are given
x=a,
y =b
n=7
and k= 4 since we have to find 5th term but k starts from zero
putting the values
[tex]={7\choose 4}a^4b^{7-4}\\={7\choose 4}a^4b^{3}\\=\frac{7!}{4!(7-4)!}a^4b^3\\=35a^4b^3[/tex]
So, 5th term is 35a^4b^3
