Respuesta :

Substitute value of y from equation 1st into 2nd, 
5x + 2y = 7
5x + 2(x - 7) = 7
5x + 2x - 14 = 7
7x = 7 + 14
x = 21 / 7
x = 3

Now, y = 3 - 7 = -4

In short, Your Answer would be Option B) (3, -4)

Hope this helps!