Find the linear approximation of the data that passes through the points (5, 3) and (20, 6). y = 15x + 9 y = 15x + 3 y=1/5x-1 y=1/5x+2

If you try the given points in the offered equations, you find the only equation that makes sense is ...
  y = 1/5x +2


If you want to determine the equation yourself, you can use the 2-point form of the equation for a line.
  y = (y2 -y1)/(x2 -x1)*(x -x1) +y1
  y = (6 -3)/(20 -5)*(x -5) +3
  y = 3/15*(x -5) +3
  y = 1/5x -1 +3
  y = 1/5x +2

the formula of a slope:

we have the points (-2, 7) and (2, 3). substitute:

answer: the slope is equal -1.