# Help Zone

### Student Question

Secondary III â€¢ 9mo.

Hi!

I am not able to find the equation of the line which goes through the following points: (-4.7) and (22.4)

Can you help me?

Mathematics

## Explanations (1)

• Explanation from Alloprof

Explanation from Alloprof

This Explanation was submitted by a member of the Alloprof team.

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Team Alloprof â€¢ 9mo.

Hello!

First of all, as we know that it is a straight line, we know the equation will take the form y = ax + b.

To find a, the slope of the line, there is a formula:

$$a = \frac {y_2 âˆ’ y_1}{x_2 âˆ’ x_1}$$

By entering the values, you will have:

$$a = \frac {4 âˆ’ 7}{22 - - 4} = \frac {-3} {26}$$

By replacing the a by its value in the formula you get this:

$$y = âˆ’ \frac{3}{26}x + b$$

Then you replaceÂ xÂ andÂ y by one of the two points that you have and as there is only theÂ b leftÂ as a variable you will be able to find its value by isolating it !

Feel free to ask us more questions if you have any!