Question

The number which should be added to twice the rational number $-\frac{7}{3}$ to get $\frac{3}{7}$ is

• A. $\frac{105}{21}$
• B. $\frac{100}{21}$
• C. $\frac{107}{21}$
• D. $\frac{-}{89}21$

Answer 1

Answer: (C)

$\frac{107}{21}$

Let the number to be added be $x$

$2\ast (-\frac{7}{3})+x=\frac{3}{7}\Rightarrow \frac{-14}{3}+x=\frac{3}{7}\Rightarrow x=\frac{14}{3}+\frac{3}{7}=\frac{14\ast 7+3\ast 3}{21}=\frac{98+9}{21}=\frac{107}{21}$