Question

Find the point-slope equation for

the line that passes through the
points (-10, -20) and (1, -9). Use
the first point in your equation.
y-[?] = [ ](x-[ ])

Answer 1

y-(-10)= 1(x-(-20))

Explanation:

Answer 2

The equation is y = x - 10.

Explanation:

Firstly, you have to find the gradient using the formula :

`m = (y2 - y1)/(x2 - x1)`

Let (x1,y1) = (-10,-20)

Let (x2,y2) = (1,-9)

`m = ( - 9 - ( - 20))/(1 - ( - 10))`

`m = ( - 9 + 20)/(1 - 10)`

`m = (11)/(11)`

`m = 1`

Next substitute first coordinate into y - y1 = m(x - x1) :

`y - y1 = m(x - x1)`

Let y1 = -20,

Let x1 = -10,

`y - ( - 20) = 1(x - ( - 10))`

`y + 20 = 1(x + 10)`

`y + 20 = x + 10`

`y = x + 10 - 20`

`y = x - 10`