Exercise 19 Page 193

We can calculate the slope by substituting the given points into the Slope Formula.

m = \frac{y _{2} - y _{1}}{x _{2} - x _{1}}

Note that it does not matter which point we choose to use for

(x_{1}, y_{1})

and

(x_{2}, y_{2}),

since the result of using the Slope Formula will be the same. Let's substitute the coordinates of points

E

and

F .

m = \frac{y _{2} - y _{1}}{x _{2} - x _{1}}

Substitute $(5, - 1)$ & $(2, - 4)$

m = \frac{- 4 - ( - 1 )}{2 - 5}

$a - (- b) = a + b$

m = \frac{- 4 + 1}{2 - 5}

Add and subtract terms

m = \frac{- 3}{- 3}

$\frac{a}{a} = 1$

m = 1

We found that the slope of the line is

m = 1 .