How do you graph the line y=-3x+3?

1 Answer
Tony B
Dec 18, 2016

Wee explanation

Explanation:

color(blue)("Main Method :")

Determine 2 separate points which are marked on the graph paper then draw a line through them.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

color(purple)("Method 1")

Substitute any sensible values into x and se what value of y you get. Then plot the points with a line going through them.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
color(purple)("Method 2 - more about teaching algebra")

color(blue)("Determine the point where "x=0)

Substitute 0 wherever x is

y=-3x+3" "->" "y=-3(0)+3

but 0xx(-3)=0 giving:

y=0+3

So at x=0" "y takes on the value of 3

So point 1 ->P_1->(x,y)=(0,3)
.......................................................................................
color(blue)("Determine the point where "y=0)

Substitute 0 wherever y is:

y=-3x+3" "->" "0=-3x+3

Add 3x to both sides

0+3x=-3x+3x+3

but -3x+3x=0

3x=0+3

Divide both sides by 3

3/3x=3/3

But 3/3=1

x=1

So point 2 ->P_2->(x,y)=(1,0)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Tony B

Related questions
See all questions in Graphs of Linear Equations
Impact of this question
17894 views around the world
You can reuse this answer
Creative Commons License