Respuesta :

y + 1/4 = -3x - 3/2
3x + y = -3/2 - 1/4
3x + y = -6/4 - 1/4
3x + y = -7/4
y + 1/4 = -3(x + 1/2)
y + 1/4 = -3x - 3/2   
multiply both sides by 4 to get rid of the fractions:
4y + 1 = -12x - 6
12x + 4y = -6 - 1
12x + 4y = -7  ← answer