Hello there! :)
Answer:
1.

2.

Explanation:
1. 3/5+4/15
First, you multiply by numerator and denominator.
3*3=9
5*3=15

Then, you had to combine by the fractions.

Add by the numbers from left to right.
9+4=13
13/15 is the final answer.
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2. 5/6-1/4
First, you multiply by 2 both sides of numerator and denominator.
5*2=10
6*2=12
10/12
3/12
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Subtract by the numerator.
10-3=7
7/12 is the final answer.
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Hope this helps!
Thanks!
Have a nice day! :)
:D
-Charlie