The graph of a function is a line that passes through the points (2,3) , (4,9) , and (7,y) . What is the value of y ?

Answer 1

(2,3) and (4,9) have a line through them with slope = 'rise over run"

= the change in y coordinates over the corresponding change in x coordinates

= (9-3)/(4-2) = 6/2 = 3

= (y-3) = 3(x-2) where (x,y) is any point on the line

y = 3x-6+3

y = 3x -3

if (7,y) is also on the line then

y =3(7)-3=21-3 = 18

(7,18) is a point on the line through all 3 points