Question

4.1 & 4.2: Write the equation of a line in slope intercept form given the graph.

Answer 1

We have the following:

1.

the formula for the slope is:

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

The points are (-5, 4) and (5, - 2)

replacing:

$m=\frac{-2-4}{5-(-5)}=\frac{-6}{5+5}=-\frac{6}{10}=-\frac{3}{5}$

The y-intercept (b) is 1, the equation of a line in slope intercept form is:

$y=mx+b$

replacing:

$y=-\frac{3}{5}x+1$

2.

The points are (- 1, - 3) and (1, 3)

replacing

$m=\frac{3-(-3)}{1-(-1)}=\frac{3+3}{1+1}=\frac{6}{2}=3$

The y-intercept (b) is 0, replacing:

$y=3x$