To solve the first equation, we will first distribute the 2 on the right side:

3x + 1 = 2x - 8y - 5

Next, we will combine like terms on the right side:

3x + 1 = 2x - 8y - 5

Subtract 2x from both sides:

x + 1 = -8y - 5

Add 8y and 5 to both sides:

x + 8y + 6 = 0

Therefore, the solution to the first equation is x + 8y + 6 = 0.

Now, let's solve the second equation. We will first distribute the 2 on the left side:

2x + 8y + 9 = 10y + 15

Next, we will combine like terms on the left side:

2x + 8y + 9 = 10y + 15

Subtract 8y from both sides:

2x + 9 = 2y + 15

Subtract 9 from both sides:

2x = 2y + 6

Divide by 2:

x = y + 3

Therefore, the solution to the second equation is x = y + 3.