Question

cuánto es 3/7 + 9/21​

Answer 1

$\frac{3}{7}+ \frac{9}{21}= \frac{(3x21)+(7x9)(}{7x21}= \frac{63+63}{147}= \frac{126}{147} =\frac{42}{49}=\boxed{\frac{6}{7}}$