Question

[(2)-¹ + (4)-¹ + (3)-¹]-¹​

Answer 1

$((2) {}^{ - 1} + (4) {}^{ - 1} + (3) {}^{ - 1} ) {}^{ - 1} \\ = ( \frac{1}{2} + \frac{1}{4} + \frac{1}{3} ) {}^{ - 1} \\ = ( \frac{6 + 3 + 4}{12} ) {}^{ - 1} \\ = ( \frac{13}{12} ) {}^{ - 1} \\ = \frac{12}{13}$

formula used is

[a-ⁿ=1/aⁿ]