Question

9.
Write down the equation of a line joining the
following points.
(a) (2, -1) (-1, 1) (b) (3.0), (0, -2)​

Answer 1

Step-by-step explanation:

a1. First, find the slope

$\frac{(y_1 - y_2)}{(x_1 - x_2)} = m \\ \frac{( - 1) - (1)}{(2) -(1)} = m \\ \frac{ - 2}{1} = m$

2. Next, use a point from the given to substitute to the slope-intercept form.

$y-y_1=m(x-x_1) \\ y - ( - 1) = ( - 2)(x - 2) \\ y + 1 - (1)= - 2x + 4 - (1) \\ y = - 2x + 3$

b1. First, find the slope

$\frac{(y_1 - y_2)}{(x_1 - x_2)} = m \\ \frac{( 0) - ( - 2)}{(3) -(0)} = m \\ \frac{ 2}{3} = m$

2. Next, use a point from the given to substitute to the slope-intercept form.

$y-y_1=m(x-x_1) \\ y - (0) = ( \frac{2}{3} )(x - 3) \\ y = \frac{2}{3} x - 2$