Question

Find the value of ${[{\left(\frac{1}{3}\right)}^{-1}-{\left(\frac{1}{4}\right)}^{-1}]}^{-1}$

• A. $-1$
• B. $0$
• C. $1$
• D. $-12$

Answer 1

Answer: (A)

$-1$

${[{\left(\frac{1}{3}\right)}^{-1}-{\left(\frac{1}{4}\right)}^{-1}]}^{-1}={[\frac{1}{\left(\frac{1}{3}\right)}-\frac{1}{\left(\frac{1}{4}\right)}]}^{-1}$
$={[3-4]}^{-1}$
$={(-1)}^{-1}$
$=-1$