Respuesta :

rearranging the first equation:-

3x  - 4y = -7 
9x + 4y = 139

12x = 132
x = 132/12 = 11
Substituting fro x in the second equation:-
9(11) + 4y = 139
4y = 139 - 99 = 40
y = 40/4 = 10

Answer x = 4 , y = 10.