Given 3x + 2Y = 3x-2y = 2, find the value of 3x-4y

Given 3x + 2Y = 3x-2y = 2, find the value of 3x-4y

If we separate the two formulas, we can get the following results
3x + 2Y = 10, 3x-2y = 20, x = 5, y = - 2.5
3x-4y=25