(1,4) (3,8) and (6,y). what is the value of y?

The formula for point slope form is:

y − y1 = m(x − x1)
 where (x1,y1) is a point on the graph and m=slope

now lets solve for the slope of our points: (1,4) (3,8)

Slope=y2-y1/x2-x1=8-4/3-1=4/2=2

Now we can plug our information into the equation

y − y1 = m(x − x1)
y-4=2(x-1)

Now lets convert it to slope intercept form

y-4=2(x-1)
add 4 to both sides
y=2(x-1)+4
y=2x-2+4
y=2x+2

Now we can solve for the missing y value in (6,y) by plugging in the x value.

y=2x+2
y=2(6)+2
y=12+2
y=14

So the ordered pair would be (6,14)

Answer=14