Steply

Graph y > x - 3

Step by step, with the reason for every step · Graphing inequalities · Algebra 1

Step by step

The question

Question: graph y > x − 3.

y > x − 3

The answer is not one point.

It is every point that makes this true.

That is a whole part of the grid.

answer = all the points that work

1 Draw the line

First we draw the line where both sides are equal: y = x − 3.

y = x − 3

The sign is more than, with no "or equal to".

So points on the line are not answers.

We draw it dashed, like the open circle on a number line.

> → dashed line

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.

b = −3.

Start on the y-axis at −3.

m = 1.

As a fraction: 1/1.

Go right 1,

then up 1.

Dot.

Join the dots: dashed.

2 Test a point

The line cuts the grid in two sides.

One side is the answer.

We test one point: (0, 0).

Zeros are easy to work with.

Put x = 0 and y = 0 in.

0 > 0 − 3
0 > −3 true

Is 0 more than −3?

Yes, that is true.

So (0, 0) is an answer.

3 Shade

So we shade the side with (0, 0).

Every point there is an answer.

4 Check

Let's check with a point in the shaded part: (−2, −1).

Put x = −2 and y = −1 in.

−1 > (−2) − 3
−1 > −5 true

True!

So the shading is right.

Let's look back.

First: draw the line.

Then: test a point.

Then: shade.

Last: check.

Answer
0 > −3 true

Your turn

Try this one yourself, then check:

Graph y > x − 2
Show the answer
dashed line y = x − 2, shade above

More from Graphing inequalities

The whole lesson: Graphing inequalities →