A planet measures 6 cm 2 weeks into an experiment and then measures 12 cm 4 weeks after that. Write the equation of the line to describe this situation if x=weeks and y=centimeters.

Question

Linear Equations:

A planet measures 6 cm 2 weeks into an experiment and then measures 12 cm 4 weeks after that. Write the equation of the line to describe this situation if x=weeks and y=centimeters.

Answer 1

Use the equation of a line formula: y=mx + b

Calculate the slope, m, (change in y over change in x):

(12-6)/(4-2) = 6/2 = 3

Plug in the coordinates of one of the points (2,6): (x = 2, y= 6)

6 = 3(2) + b

Solve for b, which equals zero.

The equation is: y = 3x