need help in simplifying this problem and solving it.

[faithin]

3y(2xz+2)-6xyz, when x = -3 , y = -4 and z = 7

I understand how to simply the operation using PEMDAS
3y(2xz+2)-6xyz = 3y(2xz+2)+-6xyz = 6xyz+6y+-6xyz= 6y
I just don't understand where to put the -3,-4, and the 7
Please help me
thanks

 

[tkhunny]

6y

If y = 5

6(y) = 6(5)

 

[Denis]

I just don't understand where to put the -3,-4, and the 7

The x and z have vanished! So just use the y.