The unchanging value of the ratio between two proportional quantities is O the constant of proportionality.
O the constant rate.
O the x-value of an ordered pair.
O the y-value of an ordered pair.

The constant of proportionality.

Step-by-step explanation:

Lets say a is directly proportional to b and k is a constant.

This can be expressed as;

a ∝ kb

This means that as the value of a rises, the value of b rise too.

k (the constant of this proportionality remain the same).

answer: 819.89 miles across america

step-by-step explanation:

step-by-step explanation:

for exempl this   system of equations   y = x - 3

                                                                y = 2x - 5

look   the line : y = x -3     ( red)

                            the line : y = 2x -5 ( bleus)