Question

Which expression can be used to find the slope of a line containing the points (–3, 2) and (7, –1

Answer 1

The short cut formula for finding equation of two points

(x₁, y₁) and (x₂, y₂)

is:

(y - y₁) / (y₂- y₁) = (x - x₁) / (x₂ - x₁).

Substituting: x₁ = -3, y₁ = 2, x₂ = 7, y₂ = -1

(y - 2) / (-1 - 2) = (x - -3) / (7 - -3)

(y - 2) / -3 = (x + 3) / (7 + 3)

(y - 2) / -3 = (x + 3) / 10

10*(y - 2) = -3*(x +3)

10y - 10*2 = -3*x - 3*3

10y - 20 = -3x - 9

10y + 3x = -9 +20

10y +3x =11

Hence equation is: 10y + 3x = 11

Hope this explains it.

Answer 2

`slope = (-1-2)/(7+3)`

Explanation:

the slope of a line containing the points (–3, 2) and (7, –1)

To find slope of a line we use formula

`slope = (y_2-y_1)/(x_2-x_1)`

(–3, 2) is (x1,y1) and (7, –1) is (x2,y2)

x1= -3, x2=7, y1=2, y2=-1

Plug in all the values in the formula

`slope = (-1-2)/(7+3)=(-3)/(10)`