While adding or subtracting rational numbers with different denominators, how will you make the denominators equal? [Page No. 49]

Rewrite each fraction as an equivalent fraction using a common denominator, usually the LCM of the two denominators.

Multiply the numerator and denominator of each fraction by whatever number makes its denominator equal to that common value (this does not change the fraction's value). Then add or subtract the numerators.

For example, $\frac{1}{4} + \frac{2}{3}$ the LCM of 4 and 3 is 12,

$$\text{so } \frac{1}{4} = \frac{3}{12} \text{ and } \frac{2}{3} = \frac{8}{12} \text{ giving } \frac{3}{12} + \frac{8}{12} = \frac{11}{12}$$