Respuesta :

Answer:

B. 4375x^4

Step-by-step explanation:

Firstly, you can just multiply it and look at the fourth term or use the binomial theorem. Either way it's B.

Answer:

4375x^4.

Step-by-step explanation:

There is a useful formula for answering these type of questions. It is:

(r + 1)th term of (x + a)^n = nCr x^(n-r) a^r.

4th term = (3 + 1)th term of (x + 5)^7

=  7C3 x^(7-3) 5^3

= 35 x^4 * 125

= 4375x^4.