Question

What is the equation of the line that passes through (2, -7) and (-1, 2)? y = -3x - 1 y = 3x + 1 y = -x - 1 y = x + 1

Answer 1

`y = - 3x - 1`

EXPLANATION

The given line passes through

(2, -7) and (-1, 2)

We find the slope using the formula,

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

`m = (2 - - 7)/( - 1 - 2)`

`m = (9)/( - 3) = - 3`

The equation is given by;

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

We substitute the values to get,

`y - - 7 = - 3(x - 2)`

Expand:

`y + 7 = - 3x + 6`

`y = - 3x + 6 - 7`

`y = - 3x - 1`

Answer 2

The answer is y=-3x - 1.

Explanation:

There are two ways to find the equation. First is to use the two-point slope form and the second is simply substitution of the given.

We simply substitute our given coordinates to our equation.

(2, - 7) and (-1, 2)

-7 = - 3(2) - 1. 2 =-3(-1) - 1

-7 = - 6 - 1. 2 = 3 - 1

-7=-7. 2 = 2

Thus, points (2,-7) and (-1,2) passes through y = - 3x - 1.