1234
of 4

Graphing Lines Using Intercepts

Here's another one:

Graph   

x + 2y = 4

1) start by making an xy table and putting a 0 in the x column and a 0 in the y column. 2) cover the x in the equation x + 2y = 4 with your finger, which shows y = 2

3) put the 2 in the y column next to the 0 in the x column. 4) cover the 2y in the equation x + 2y = 4 with your finger, which shows x = 4

5) put the 4 in the x column next to the 0 in the y column. 6) graph a line using the two intercepts from the xy chart... a line through the points ( 0 , 2 ) and ( 4 , 0 )

Always label the two points on your graph!  Why?

Three reasons:

a)  Your teacher will require it.

b)  It's polite.

c)  If your drawing skills... uh... stink, at least your teacher will know what you meant!

Sometimes I call this the "finger cover-up method."

TRY IT:

Graph x - y = 3

by finding the intercepts.

Graph -3x + 4y = 12by finding the intercepts.