Question

What is the `x`-intercept of the line that contains the points `(-4, 1)` and `(-7, 2)` in the standard `(x, y)` coordinate plane?

Answer 1

(see below)

Explanation:

Find the equation of the line:

1. Find the gradient using `dy/dx`
   `(1-2)/(-4+7) = -1/3`

2. Take 1 coordinate point and use `y-y_1 = m (x-x_1)` to find the equation of the line
   `y-1 = -1/3 ( x - (-4) )`
   `y-1 = -1/3x - 4/3`
   `y = -1/3x - 1/3`

3. substitute 0 into y to find the x-intercept.

`y= -1/3x`