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Find the values of each of the following
(i) $ 3^{-1}+4^{-1} $
(ii) $ \left(3^{0}+4^{-1}\right) \times 2^{2} $
(iii) $ \left(3^{-1}+4^{-1}+5^{-1}\right)^{0} $
(iv) $ \left\{\left(\frac{1}{3}\right)^{-1}-\left(\frac{1}{4}\right)^{-1}\right\}^{-1} $
To do:
We have to find the values of each of the given expressions.
Solution:
We know that,
$a^{-m}=\frac{1}{a^{m}}$
$a^o=1$
Therefore,
(i) $3^{-1}+4^{-1}=\frac{1}{3}+\frac{1}{4}$
$=\frac{1\times4+1\times3}{12}$ (LCM of 3 and 4 is 12)
$=\frac{4+3}{12}$
$=\frac{7}{12}$
(ii) $(3^{0}+4^{-1}) \times 2^{2}=(1+\frac{1}{4})\times4$
$=\frac{1\times4+1}{4}\times4$
$=\frac{5}{4}\times4$
$=5$
(iii) $(3^{-1}+4^{-1}+5^{-1})^{0}=(\frac{1}{3}+\frac{1}{4}+\frac{1}{5})^o$
$=1$
(iv) $[{(\frac{1}{3})^{-1}-(\frac{1}{4})^{-1}}]^{-1} =[{(3)^{1}-(4)^{1}}]^{-1}$
$=(3-4)^{-1}$
$=(-1)^{-1}$
$=\frac{1}{(-1)^{1}}$
$=\frac{1}{-1}$
$=-1$
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