Step by step
The question
Question: solve by graphing y = 2x + 1 and y = 2x − 3.
The answer is a point that is on both lines.
So we draw both lines and see where they meet.
1 Graph line ①
Draw the grid.
The x-axis goes across.
The y-axis goes up and down.
They meet at 0.
That point is called the origin.
In ①, b = 1.
Start on the y-axis at 1.
m = 2.
As a fraction: 2/1.
Go right 1,
then up 2.
Dot.
Join the dots with a straight line.
2 Graph line ②
In ②, b = −3.
Start on the y-axis at −3.
m = 2.
As a fraction: 2/1.
Go right 1,
then up 2.
Dot.
Join the dots with a straight line.
3 Where they meet
Both have slope 2, but they start at different places: 1 and −3.
So they are parallel: they never meet.
So there is no solution.
Let's look back.
First: graph line ①.
Then: graph line ②.
Last: where they meet.