Let's simplify each equation:

1) 3 - (2x - 5)3 = 17 - 5(x - 2)

Distribute the negative sign on the left side:
3 - 6x + 15 = 17 - 5x + 10

Combine like terms:
-6x + 18 = -5x + 27

Subtract -18 from both sides:
-6x = -5x + 9

Subtract -5x from both sides:
-6x + 5x = 9

-1x = 9
x = -9

2) 3(7x - 4) - (x - 6) = 15x - 4(x - 3)

Distribute the 3 on the left side:
21x - 12 - x + 6 = 15x - 4x + 12

Combine like terms:
20x - 6 = 11x + 12

Subtract 20x from both sides:
-6 = -9x + 12

Subtract 12 from both sides:
-6 - 12 = -9x

-18 = -9x

Divide -9 from both sides:
-18 / -9 = x

x = 2

Therefore, the solutions to the given equations are x = -9 and x = 2.