Equations of lines in the coordinate plane

Question

1. What is the slope of the line passing through the points (2, 7) and (-1, 3)

 

A. 2/7

B. 3/4

C. 4/3

D. 1/3

Answer 1

Hi Anon;

Great question.  You should be proud to ask it!

slope=(y-y₁)/(x-x₁)

It is the change of y, divided by the change of x.  It is also called rise (up and down) over run (left and right).

slope=(3-7)/(-1-2)

slope=-4/-3=4/3

A negative divided by a negative yields a positive number.

The answer is C.

Answer 2

In my classroom, we use the stack and subtract method.

 

 (2 , 7)

-(-1, 3)

 (3 , 4)

 

Then take the second number over the first since slope is rise over run.

 

4

3

 

The Correct answer is C.