To solve the first equation, we would first distribute the 7 on the left side:

7(3) - 7(2x) = 15(1) - 15x
21 - 14x = 15 - 15x

Next, we would move all terms involving x to one side and constants to the other side:

21 - 15 = 14x - 15x
6 = -x
x = -6

Therefore, the solution to the first equation is x = -6.

To solve the second equation, we first need to combine like terms:

7y - 11/12 - y + 1/4 = 2y + 5/3
6y - 11/12 + 1/4 = 2y + 5/3
6y - 11/12 + 3/12 = 2y + 20/12
6y - 8/12 = 2y + 20/12
6y - 2y = 28/12
4y = 28/12
y = 7/3

Therefore, the solution to the second equation is y = 7/3.