Question

Anya found the slope of the line that passes through the points (–7, 4) and (2, –3). Her work is shown below. Let (x2, y2) be (–7, 4) and (x1, y1) be (2, –3). m = x2-x1/y2-y1 = -7-2/4-(-3)= -9/7 The slope is -9/7 What error did she make?

Answer 1

m=y2-y1/x2-x1 not x2-x1/y2-y1, that is her error

Answer 2

Explanation:

The points (-7, 4) and (2, -3) through which line is passing.

The equation of line passing two point is given as:
`(x_1,y_1)(x_2,y_2)`

`(y-y_1)=((y_2-y_1))/((x_2-x_1))* (x-x_1)`

`(y-y_1)=m* (x-x_1)`

m = slope of the line

The equation of the line will be:

`(y-4)=((-3-(4)))/((2-(-7)))* (x-(-7))`

`(y-4)=(-7)/(9)* (x+7)`

Slope of the line =
`m=(-7)/(9)`

The error made by the Anya was that she has used wrong formula.

`m = (x_2-x_1)/(y_2-y_1)` (Wrong formula)