Respuesta :

4x+7y=47  /*4 ------>16x + 28y=188
5x-4y=-5  /*7  -------->35x-28y=-35

16x + 28y=188,   add this two equations
35x-28y=-35

16x + 28y+35x-28y=188-35
16x +35x=188-35
51x =153m
x=3

5x-4y=-5 
5*3-4y=-5 
15-4y=-5
4y=15+5
4y=20
y=5
 
Answer (3,5), B