Select the correct answer.

Two points located on [tex]$\overleftarrow{JK}$[/tex] are [tex]$J(1,-4)$[/tex] and [tex]$K(-2,8)$[/tex]. What is the slope of [tex]$\overleftarrow{JK}$[/tex]?

A. -4
B. -2
C. [tex]$-\frac{1}{4}$[/tex]
D. [tex]$\frac{1}{4}$[/tex]
E. 4



Answer :

To determine the slope of the line passing through the points [tex]\( J(1, -4) \)[/tex] and [tex]\( K(-2, 8) \)[/tex], we can use the slope formula. The slope [tex]\( m \)[/tex] between two points [tex]\((x_1, y_1)\)[/tex] and [tex]\((x_2, y_2)\)[/tex] is calculated as:

[tex]\[ m = \frac{y_2 - y_1}{x_2 - x_1} \][/tex]

For the points [tex]\( J(1, -4) \)[/tex] and [tex]\( K(-2, 8) \)[/tex]:
- [tex]\((x_1, y_1) = (1, -4)\)[/tex]
- [tex]\((x_2, y_2) = (-2, 8)\)[/tex]

Plug these values into the slope formula:

[tex]\[ m = \frac{8 - (-4)}{-2 - 1} \][/tex]

Simplify the numerator and the denominator:

[tex]\[ = \frac{8 + 4}{-2 - 1} \][/tex]

[tex]\[ = \frac{12}{-3} \][/tex]

When we divide 12 by -3, we get:

[tex]\[ m = -4 \][/tex]

Thus, the slope of [tex]\(\overleftarrow{ JK }\)[/tex] is [tex]\(\boxed{-4}\)[/tex].