Answer:
1)
[tex]\text{ Slope = -3}[/tex]
2)
[tex]y+4=-\frac{7}{8}(x-7)[/tex]
3)
[tex]y=-\frac{7}{8}x+\frac{17}{8}[/tex]
Step-by-step explanation:
We want to write the equation of the line that passes through the points (7, -4) and (-1, 3) first in point-slope form and then in slope-intercept form.
1)
First and foremost, we will need to find the slope of the line. So, we can use the slope-formula:
[tex]m=\frac{y_2-y_1}{x_2-x_1}[/tex]
Let (7, -4) be (x₁, y₁) and let (-1, 3) be (x₂, y₂). Substitute them into our slope formula. This yields:
[tex]m=\frac{3-(-4)}{-1-7}[/tex]
Subtract. So, our slope is:
[tex]m=\frac{7}{-8}=-7/8[/tex]
2)
Now, let's use the point-slope form:
[tex]y-y_1=m(x-x_1)[/tex]
We will substitute -7/8 for our slope m. We will also use the point (7, -4) and this will be our (x₁, y₁). So, substituting these values yield:
[tex]y-(-4)=-\frac{7}{8}(x-7)[/tex]
Simplify. So, our point-slope equation is:
[tex]y+4=-\frac{7}{8}(x-7)[/tex]
3)
Finally, we want to convert this into slope-intercept form. So, let's solve for our y.
On the right, distribute:
[tex]y+4=-\frac{7}{8}x+\frac{49}{8}[/tex]
Subtract 4 from both sides. Note that we can write 4 using a common denominator of 8, so 4 is 32/8. This yields:
[tex]y=-\frac{7}{8}x+\frac{49}{8}-\frac{32}{8}[/tex]
Subtract. So, our slope-intercept equation is:
[tex]y=-\frac{7}{8}x+\frac{17}{8}[/tex]
And we're done!