Question2
D. 3 Write the equation of a linear function
Video
A line passes through the points and . Write its equation in slope-intercept form.
Write your answer using integers, proper fractions, and improper fractions in simplest form.
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Studdy Solution
STEP 1
What is this asking?
We need to find the equation of a line that goes through two given points and write it in slope-intercept form, which is .
Watch out!
Don't mix up the and coordinates!
Also, remember to simplify the fraction in the final equation.
STEP 2
1. Find the slope
2. Find the y-intercept
3. Write the equation
STEP 3
Alright, let's **start** by finding the **slope**!
The slope, which we call , tells us how steep our line is.
We can find it using the formula:
where and are our two points.
STEP 4
Let's **label** our points.
We'll call as point 1, so and .
And will be point 2, so and .
STEP 5
Now, let's **plug** these values into our **slope formula**:
STEP 6
**Simplify** the numerator and the denominator:
STEP 7
**Divide** by to get our **slope**: So, our line has a slope of , meaning it goes downwards pretty steeply!
STEP 8
Great, we've got our slope!
Now, let's find the **y-intercept**, which we call .
This is the point where our line crosses the y-axis.
We can use the slope-intercept form of a linear equation, , and plug in one of our points and the slope we just found.
STEP 9
Let's use point 1, , and our slope, . **Substitute** these values into the equation:
STEP 10
**Simplify** the equation:
STEP 11
To **isolate** , we can add to both sides of the equation:
STEP 12
So, our **y-intercept** is .
This means our line goes right through the origin!
STEP 13
We have our **slope**, , and our **y-intercept**, .
Now, we just need to **plug** these values back into the slope-intercept form, .
STEP 14
**Substitute** the values:
STEP 15
**Simplify**:
STEP 16
The equation of the line in slope-intercept form is .
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