Question

Fill in the blanks:

$\frac{8}{21}+\frac{5}{7}=\_\_\_$

Answer 1

• Step 1: The least common denominator (LCD) of $7$ and $21$ is $21$. Make the denominator as $21$ for both the fractions.

$\frac{8}{21}=\frac{8\times 1}{21\times 1}=\frac{8}{21}$;

$\frac{5}{7}=\frac{5\times 3}{7\times 3}=\frac{15}{21}$

• Step 2: Add the numerators and write the sum over the common denominator.

$\frac{8}{21}+\frac{15}{21}=\frac{8+15}{21}=\frac{23}{21}$

• Hence, $\frac{8}{21}+\frac{5}{7}=\frac{23}{21}$.