Aline passing through which of the following pairs of coordinates represents a proportional relationship?
(2.5, 5) and (3, 5.5)
(1.25, 2.25) and (2.5, 5)
(1.3, 3.3) and (2.3, 4.3)
(1.25, 2.5) and (3.75, 7.5)

the answer is (1.25, 2.5) and (3.75, 7.5)

Step-by-step explanation:

1. To be a proportional relationship, the ratio between the y-coordinates must be equal to the ratio of the x-coordinates. For example, for the first choice we have:

ratio for x coordinate: 3/2.5  =1.2

ratio for y coordinate: 5.5/5 =1.1

The ratios are not the same and consequently it is not a proportional relationship.

2. The correct answer is  (1.25, 2.5) and (3.75, 7.5) because if we check the ratios for the coordinates we get

ratio for x coordinate: 3.75/1.25 = 3

ratio for y coordinate: 7.5/2.5 =3

In this case we can see the ratios are equal, hence we can state it is a proportional relationship.

5x+40

5(x + 8)

7x - 49

7(x - 7)

18x + 9

9(2x + 1)

15x - 10

5(3x - 2)

step-by-step explanation:

for number one all you have to do is factor 5 out of 5x + 40

for number 2 factor 7 out of 7x - 49

for number three factor 9 out of 18x + 9

for number four factor 5 out of 15x - 10