4x + 3y = 19 multiply this by 4
5x - 4y = 47 multiply this by 3:-
16x + 12y = 76..............(1)
15x - 12y = 141............(2)
Add (1) + (2);-
31x = 217
x = 7
Now plug = 7 into the first equation:-
4(7) + 3y = 19
3y = 19 - 28 = -9
t = -3
Solution is x = 7, y = -3.