Suppose y varies directly as x Write a direct variation equation that relates x and y. Then solve.

if y=15 when x=2, find y when x=8

y=7.5x, y=60

Step-by-step explanation:

you have to consider x as the input and y as output

when input  x=2 the output  y=15  so it grew by 7.5 so we can say that y= 2*7.5

in general the equation is y= 7.5*x

when x=8 we will have y=7.5*8=60

1) is right

step-by-step explanation:

y = 3x+4

step-by-step explanation:

to find the slope

slope = (y2-y1)/ (x2-x1)

    = (-8-4)/ (-4-0)

    = -12/-4

  = 3

using the slope intercept form of a line

y= mx+b

we know the slope is 3

we know the y intercept is 4 ( the point where it crosses the y axis or x=0)

y = 3x+4