Question

A line passing through which of the following pairs of coordinates represents a proportional relationship?

(1.25, 2.5) and (3.75, 7.5)
(1.25, 2.25) and (2.5, 5)
(2.5, 5) and (3, 5.5)
(1.3, 3.3) and (2.3, 4.3)

Answer 1

1.25x = 3.75
2.5y=7.5

do these for all (x,y) pairs

when the x and y variable are the same --- that will be a proportional relationship