The teacher gave this question and i'm having a hard time answering it. we're allowed to use a calculator.

The equation is:

The stopping distance at 65mph will be 250ft

Why?

We can find the equation using any of the input/outputs given in the table.

The quadratic equation will be:

Also, remember that if the speed of the car is 0, the stopping distance will be also 0, so, the constant value "c" is not necessary in this case.

Let's use the inputs 35 and 45, and their outputs, 96 and 140.

We will have two equations with two variables, so, we can solve it:

Substituting 35 and 96:

Subsituting 45 and 140:

Now, we have two equations, let's solve it by elimination: Multiply the first by 9, and the second equation by 7, and then, substract the first one from the second one:

Now, subsitutitng "a" into the first equation to find "b" we have:

Hence, we have that the quadratic equation will be:

Now, predicting the stopping distance and 65mph we have:

Have a nice day!