It costs $57.19 to fill up a 19 gallon gas tank and $54.18 to fill up an 18 gallon tank.

What is the constant of proportionality that relates the cost in dollars,
y, to the number of gallons of gas, x?

y=3.01x

Step-by-step explanation:

We can see that since 19 gallons cost $57.19 and 18 gallons cost $53.18, 1 gallon (19-18) must cost $3.01.

Therefore, y=3.01x

You can check this with algebra

- "runner b is moving at a slower rate."

- "the graphs shown are graphs of distance(km) against time(min).

the slopes of this graphs are are given by:

slope = (change in y)/(change in x)

= (change in distance)/(change in time)

this is the formula for finding the speed. so, the slope of these graphs represent the speed of the runner.

taking each division in the graph to represent 1 on both axis:

runner a ⇒ speed = (2-0)/(1-0)

= 2/1

= 2 km/min

runner b ⇒ speed = (3-0)/(3-0)

= 3/3

= 1 km/min

this shows that   runner b is moving at a slower rate."

answer: do we write it

step-by-step explanation: