Question

Question 94 (f)

Taking $x=\frac{-4}{9},y=\frac{5}{12}$ and $z=\frac{7}{18}$, find
The sum of reciprocals of x and y

Answer 1

Given, $x=\frac{-4}{9},y=\frac{5}{12}andz=\frac{7}{18}$
Reciprocal of x and y is $\frac{1}{x}and\frac{1}{y}.$
$\therefore$ Sum of reciprocals $=\frac{1}{x}+\frac{1}{y}=\frac{1}{\frac{-4}{9}}+\frac{1}{\frac{5}{12}}$
$=\frac{-9}{4}+\frac{12}{5}=\frac{-9\times 5+12\times 4}{20}=\frac{-45+48}{20}$ [$\because$ LCM of 4 and 5 = 20]
$=\frac{3}{20}$