Question

Enter the equation that describes the line in slope-intercept form. The points (7, 9) and (2, −9) are on the line y = .

Answer 1

Given:

A line passes through two points (7, 9) and (2, −9).

To find:

The slope intercept form of the line.

Solution:

A line passes through two points (7, 9) and (2, −9), so the equation of line is

$y-y_1=\dfrac{y_2-y_1}{x_2-x_1}(x-x_1)$

$y-9=\dfrac{-9-9}{2-7}(x-7)$

$y-9=\dfrac{-18}{-5}(x-7)$

$y-9=\dfrac{18}{5}(x-7)$

Using distributive property, we get

$y-9=\dfrac{18}{5}(x)-\dfrac{126}{5}$

$y=\dfrac{18}{5}(x)-\dfrac{126}{5}+9$

$y=\dfrac{18}{5}x+\dfrac{-126+45}{5}$

$y=\dfrac{18}{5}x-\dfrac{81}{5}$

Therefore, the slope intercept form of the line is $y=\dfrac{18}{5}x-\dfrac{81}{5}$.