Steply

Graph 5x + 2y = 10

Step by step, with the reason for every step · Graphing Ax + By = C · Algebra 1

Step by step

The question

Question: graph 5x + 2y = 10.

5x + 2y = 10

Every point on the x-axis has y = 0.

Every point on the y-axis has x = 0.

on the x-axis: y = 0
on the y-axis: x = 0

1 Cross the x-axis

On the x-axis, y = 0.

Put 0 in place of y.

5x + 2 × 0 = 10

2 times 0 is 0.

Adding 0 changes nothing.

5x = 10

5x means 5 times x.

We want just x.

To remove times 5, we divide by 5.

We do it on both sides, so they stay equal.

5x5 = 105

5 divided by 5 is 1.

So just x is left.

10 divided by 5 is 2.

105 = 2

So x = 2.

x = 2

So the line crosses the x-axis at (2, 0).

This point is called the x-intercept.

→ (2, 0)

2 Cross the y-axis

On the y-axis, x = 0.

Put 0 in place of x.

5 × 0 + 2y = 10

5 times 0 is 0.

0 plus 2y is just 2y.

2y = 10

2y means 2 times y.

We want just y.

To remove times 2, we divide by 2.

We do it on both sides, so they stay equal.

2y2 = 102

2 divided by 2 is 1.

So just y is left.

10 divided by 2 is 5.

102 = 5

So y = 5.

y = 5

So the line crosses the y-axis at (0, 5).

This point is called the y-intercept.

→ (0, 5)

3 Draw the 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.

Put the two points on the grid: (2, 0)

and (0, 5).

Join the dots with a straight line.

It keeps going both ways.

4 Check

Let's check with another point on the line: (4, −5).

It sits on a grid corner.

Put x = 4 and y = −5 into 5x + 2y.

5(4) + 2(−5) = 20 − 10 = 10

We get 10, the same as the right side.

So the line is right!

Let's look back.

First: cross the x-axis.

Then: cross the y-axis.

Then: draw the line.

Last: check.

Answer
y = 5

Your turn

Try this one yourself, then check:

Graph 3x + 2y = 6
Show the answer
crosses at (2, 0) and (0, 3)

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