Question

A train is traveling at a constant speed in miles per hour. Hours (x) Miles (y) Which equation models the data in the table? 1 20 2 100 O y=20x 3 180 O y = x + 80 4 260 5 340 Oy=60x – 80 O y = = 80x — 60​

Answer 1

Given:

A train is traveling at a constant speed in miles per hour.

The table of value is:

Hours (x)     Miles (y)

     1                  20

     2                 100

     3                 180

     4                 260

     5                 340

To find:

The equation for the given data table.

Solution:

It is given that the train is traveling at a constant speed in miles per hour. So, it is a linear relationship.

Choose any two point from the given table of value. Let the two points are (1,20) and (2,100). So, the equation of the line is:

$y-y_1=\dfrac{y_2-y_1}{x_2-x_1}(x-x_1)$

$y-20=\dfrac{100-20}{2-1}(x-1)$

$y-20=\dfrac{80}{1}(x-1)$

$y-20=80(x-1)$

Add 20 on both sides.

$y=80(x-1)+20$

$y=80x-80+20$

$y=80x-60$

Therefore, the correct option is D.