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Use the Point-slope form. Then, rewrite into slope-intercept form.
Example Solution: y=4x-7
Equations in point-slope form follow a specific format.
y- y_1= m(x- x_1)
In this form, m is the slope of the line and ( x_1, y_1) is a point on the line. Here we are given that the line passes through known points.
| x | 1 | 2 | 3 |
|---|---|---|---|
| y | - 3 | 1 | 5 |
To determine the slope of the line, we can calculate the slope by substituting only two points of the given table into the Slope Formula.
Substitute ( 1, - 3) & ( 2, 1)
Now that we know the slope of the line is 4, we can write the equation of the line in point-slope form. We can use either of the given points as (x_1,y_1) in our equation. Let's use ( 2, 1). y-y_1=m(x-x_1) ⇕ y- 1= 4(x- 2) Since any point on the line could be used to form a point-slope equation, there are infinitely many possible equations. To write a unique equation for this line, we will rewrite it in slope-intercept form.
Distribute 4
Multiply
LHS+1=RHS+1
Add terms
Please note that any point on the line can be used to form a point-slope equation. Therefore, our equation is only one of infinitely many possible equations!