To solve this proportion, we can cross multiply.

(2x + 1)(15) = (3 - 7x)(5)

Expanding both sides:

30x + 15 = 15 - 35x

Combining like terms:

30x + 15 = -35x + 15

Add 35x to both sides:

65x + 15 = 15

Subtract 15 from both sides:

65x = 0

Divide by 65:

x = 0

Therefore, the value of x that satisfies the proportion 2x + 1:3 - 7x + 5:15 = x - 2:5 is x = 0.