The easiest way to solve this system of equations is by elimination. Both equations have a 3x term, so we can basically subtract the equations to cancel the 3x. Then we will be left with a single variable to solve for.
(3x + y = -4)
-(3x -4y = 6)
Distribute the negative:
(3x + y = -4)
(-3x + 4y = -6)
Now add the equations together term by term:
0x + 5y = -10
5y = -10
y = -2
Plug y = -2 into either equation to find x.
3x + (-2) = -4
3x = -2
x = -2/3
So the answer as an ordered pair is (-2/3, -2)