2/5+3/10 We need to find the lowest common Denominator. which is 10
2/5 /10 look at the Denominator. How many times can 5 go into 10? Twice :) so 2 times the the Numerator (2) will equal 4 new fraction. 4/10
3/10 /10 Same steps. How many times can 10 got into 10? once :) so 1 times the Numerator (3) will equal 3 new fraction 3/10
So now we have common Denominators 4/10 + 3/10 = 7/10

armmermom2x

2/5+3/10
find the lcd which is 10
4/10+3/10
the answer is 7/10