Question 5183
Using the proportion method helps to get the answer.

2/(x+3) = 5/x

Multiply 2 times X
Multiply 5(x+3)

5x + 15 = 2x
Subtract 5x from both sides
15 = -3x
-5 = x

Check your answer
2/(-5+3) = 5/5
Cross multiply
2 x 5 = 10
5(-5+3) = 5(-2) = 10

There is your answer.  Hope that helps.