what is the point of intersection between the lines 3y-4x=12 and 2x=2y+3

As these are simultaneous equations you will need to get a coefficient of either x or y on one side and then substitute it within the other equation. Using the second equation you can divide by 2 leading to x=y+3/2 . Then using this the first equation can also be written as 3y-4(y+3/2) = 12. expanding this gives -y-6=12 and so y=-18. You then plug this into the first equation so 3(-18)-4x=12 so x=16.5.
you can check your answer by plugging both numbers back into the second equation.