Question

what is the answer to this problem 3/10+2/5=

Answer 1

3/10 + 2/5
= 3/10 + 2/2(2/5)
= 3/10 + 4/10
= 7/10

Answer 2

To add two fractions, the denominators have to be the same. 

Make the denominators the same:
$\dfrac{3}{10} + \dfrac{2}{5}$

$\dfrac{3}{10} + \dfrac{2\times 2}{5\times 2}$

$\dfrac{3}{10} + \dfrac{4}{10}$

Combine them:
$\dfrac{7}{10}$