Question

Which expression can be used to determine the slope of the line that passes through the points (–7, 3) and (1, –9)?

Answer 1

-9 - 3 / 1 - (-7)
This can be simplified to -12/8 or -3/2.

Answer 2

To find the slope of a line given two points, you should use the formula, $Slope= \frac{ y_{2}-y_{1} }{ x_{2}- x_{1}}$.

In this exercise is given the coordinates of two points and it is asked to find the slope of a line which intercepts both points, which are (-7,3) and (1,-9). To find the slope, you should substitute the given coordinates into the previous mention formula.

$Slope= \frac{ y_{2}-y_{1} }{ x_{2}- x_{1}}$
$Slope= \frac{(3--9)}{(-7-1)}$
$Slope= \frac{12}{-8}$
$Slope=-1.5$

The slope of the line which passes through the coordinates (-7,3) and (1,9) is $\frac{-6}{4}$ or -1.5.