Respuesta :

slope= rise/run = Δy/Δx = (y2 - y1)/(x2 - x1) = (9-1)/(3-1) = 8/2 = 4

so D.) 4
To calculate the gradient/slope of a linear graph/line:
(y(1) - y) / (x(1) - x)
NOTE: the (1) doesn't mean anything, I'm just showing you that x(1) and y(1) comes from a different point from x and y

In this case:
gradient of line = (9 - 1) / (3 - 1)
= 4

Therefore the answer is D