Answer: The fourth term is [tex]5000x^2.[/tex]
Step-by-step explanation: We are given to find the fourth term in the expansion of the following binomial :
[tex]B=(2x+5)^5.[/tex]
We know that
the r-th term in the expansion of the binomial [tex](a+x)^n[/tex] is given by
[tex]T_r=^nC_ra^{n-(r-1)}b^{r-1}.[/tex]
For the given term, we have
n = 5 and r = 4.
Therefore, fourth term is given by
[tex]T_4\\\\=^5C_{4-1}(2x)^{5-(4-1)}5^{4-1}\\\\=^5C_3(2x)^25^3\\\\=\dfrac{5!}{3!(5-3)!}\times4x^2\times125\\\\\\=\dfrac{5\times4}{2\times1}\times 500x^2\\\\=5000x^2.[/tex]
Thus, the fourth term is [tex]5000x^2.[/tex]
