Question

A car was traveling at a constant speed. The driver of the car increased the car's speed at a constant rate. The table shows the speed of the car at two different times after the driver began to increase the car's speed. SPEED OF CAR Time (seconds) Speed (meters per second) 3 11 7 19 What was the speed of the car, in meters per second, when the driver began to increase the car's speed? A. 2 B. 5 C. 8 D. 11 E. 19

Answer 1

Okay, here we have this:

The point are: (3, 11) and (7,19)

Let's find the slope:

m=(19-11)/(7-3)=8/4=2

And replacing in the equation of the line:

y-11=2(x-3)

y-11=2x-6

y=2x-6+11

y=2x+5

And replacing in the second x=0 to obtain the car's speed when the driver began to increase:

y=2(0)+5

y=0+5

y=5

Finally we obtain that the correct answer is the option B.