Steply

Make a table and graph y = 1/2x + 1

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

Step by step

The question

Question: graph y = (1/2)x + 1 using a table of values.

y = 12x + 1

We pick some x values.

We work out y for each one.

Each x and y make a point.

1 Choose x values

The slope has 2 at the bottom.

So we pick x values that 2 goes into: −2, 0 and 2.

Then y comes out whole.

x = −2, 0, 2: 2 goes in

Two points make a line.

The third one checks them.

2 Work out y

Put x = −2 in.

We get y = 0.

x = −2: y = 12(−2) + 1 = −1 + 1 = 0
0

Now x = 0 in.

We get y = 1.

x = 0: y = 12(0) + 1 = 0 + 1 = 1
1

Now x = 2 in.

We get y = 2.

x = 2: y = 12(2) + 1 = 1 + 1 = 2
2

3 Plot the points

Draw the grid.

Each column is a point: x on top, y under it.

The first one is (−2, 0).

Put a dot.

Careful!

The x on top comes first, then the y under it: (−2, 0).

Many people write the y first.

Careful: not (0, −2) ✗

(0, 1).

Dot.

(2, 2).

Dot.

4 Draw the line

The three dots line up.

Join the dots with a straight line.

It keeps going both ways.

5 Check

Let's check with one more x: x = 4.

We get y = 3.

x = 4: y = 12(4) + 1 = 2 + 1 = 3

The point (4, 3) is on our line.

So the graph is right!

Let's look back.

First: choose x values.

Then: work out y.

Then: plot the points.

Then: draw the line.

Last: check.

Answer
2

Your turn

Try this one yourself, then check:

y = 12x + 4
Show the answer
(−2, 3), (0, 4), (2, 5)

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