| The value of (?) in expression \[{{7}^{8.9}}+{{(343)}^{1.7}}\times {{(49)}^{4.8}}={{7}^{?}}\] is |
A) 13.4
B) 12.8
C) 11.4
D) 9.6
E) None of these
Correct Answer: A
Solution :
| \[{{7}^{?}}={{7}^{8.9}}\div {{(343)}^{1.7}}\times {{(49)}^{4.8}}\] |
| \[\Rightarrow \]\[{{7}^{?}}=\frac{{{7}^{8.9}}\times {{({{7}^{2}})}^{4.8}}}{{{({{7}^{3}})}^{1.7}}}\]\[\Rightarrow \]\[{{7}^{?}}=\frac{{{7}^{8.9\,+\,\,9.6}}}{{{7}^{5.1}}}\] |
| \[\Rightarrow \]\[{{7}^{?}}=\frac{{{7}^{18.5}}}{{{7}^{5.1}}}\] |
| \[\Rightarrow \]\[{{7}^{?}}={{7}^{18.5\,\,-5.1}}={{7}^{13.4}}\] |
| \[\Rightarrow \] \[?=13.4\] |
You need to login to perform this action.
You will be redirected in
3 sec
