Question

Carry out the following subtraction involving a rational number.

${\displaystyle \frac{7}{11}-\frac{3}{7}}$

Answer 1

${\displaystyle \frac{7}{11}-\frac{3}{7}}$

Now, LCM of 11 and 7 is 77.

${\displaystyle \frac{7}{11}-\frac{3}{7}}$

${\displaystyle =\frac{7\times 7}{11\times 7}-\frac{3\times 11}{7\times 11}}$

${\displaystyle =\frac{49}{77}-\frac{33}{77}}$

${\displaystyle =\frac{49-33}{77}}$

${\displaystyle =\frac{16}{77}}$