Respuesta :

mhanifa

Answer:

  • y = -6

Step-by-step explanation:

If the three points are collinear, the slopes of RS and ST are same:

  • m(RS) = (4 - 8)/(1 + 1) = -4/2 = -2
  • m(ST) = (y - 4)/(6 - 1) = (y - 4)/5

Since the sloes are equal we have the following equation:

  • (y - 4)/5 = -2
  • y - 4 = -10
  • y = -10 + 4
  • y = -6

Slopes must be equal

slope of RS

  • m=4-8/1+1
  • m=-4/2
  • m=-2

Now

Slope of ST=-2

  • y-4/6-1=-2
  • y-4/5=-2
  • y-4=-10
  • y=-10+4
  • y=-6