Question

Write an equation in point-slope form and in slope-intercept form.

Answer 1

The point-slope form:

$y-y_1=m(x-x_1)$

The slope-intercept form:

$y=mx+b$

The formula of a slope:

$m=\dfrac{y_2-y_1}{x_2-x_1}$

We have the points (1, -5) and (-3, -7). Substitute:

$m=\dfrac{7-(-5)}{-3-1}=\dfrac{12}{-4}=-3\\\\y-(-7)=-3(x-(-3))\\\\\boxed{y+7=-3(x+3)}$

Rewrite to the slope-intercept form:

$y+7=-3(x+3)$           use distributive property

$y+7=-3x-9$       subtract 7 from both sides

$\boxed{y=-3x-16}$