A) \[9{{a}^{2}}\]
B) \[10{{a}^{3}}\]
C) \[10{{a}^{2}}\]
D) \[10a\]
Correct Answer: B
Solution :
In the expansion of \[{{\left( {{x}^{2}}+\frac{a}{x} \right)}^{5}}\] the general term is \[{{T}_{r+1}}={{\,}^{5}}{{C}_{r}}{{({{x}^{2}})}^{5-r}}{{\left( \frac{a}{x} \right)}^{r}}={{\,}^{5}}{{C}_{r}}{{a}^{r}}{{x}^{10-3r}}\] Here, exponent of x is \[10-3r=1\Rightarrow r=3\] \[\therefore \] \[{{T}_{2+1}}={{\,}^{5}}{{C}_{3}}{{a}^{3}}x=10{{a}^{3}}.x\] Hence coefficient of x is\[10{{a}^{3}}\].
You need to login to perform this action.
You will be redirected in
3 sec
