Question:
Tick (✓) the correct answer
The value of $x$ for which $\left(\frac{7}{12}\right)^{-4} \times\left(\frac{7}{12}\right)^{3 x}=\left(\frac{7}{12}\right)^{5}$, is
(a) $-1$
(b) 1
(c) 2
(d) 3
Solution:
(d) 3
$\left(\frac{7}{12}\right)^{-4} \times\left(\frac{7}{12}\right)^{3 x}=\left(\frac{7}{12}\right)^{5}$
$\Rightarrow\left(\frac{7}{12}\right)^{-4+3 x}=\left(\frac{7}{12}\right)^{5}$
$\Rightarrow 3 x-4=5$
$3 x=9$
or $x=\frac{9}{3}=3$
Click here to get exam-ready with eSaral
For making your preparation journey smoother of JEE, NEET and Class 8 to 10, grab our app now.