Answer:
B. [tex]5x^4+5x^3[/tex]
Step-by-step explanation:
Given,
[tex]f(x) = 5x^3[/tex]
[tex]g(x) = x + 1[/tex]
We know that,
[tex](f\cdot g)(x) = f(x).g(x)[/tex]
[tex]\implies (f\cdot g)(x) = 5x^3(x+1)[/tex]
[tex]=5x^3.x + 5x^3.1[/tex] ( Distribution property of multiplication )
[tex]=5x^{3+1}+5x^3[/tex] ( Product of powers property )
[tex]=5x^4+5x^3[/tex]
Hence, option B is correct.
