Question

How do you write the equation of the line in slope intercept form that passes through the points (2, -5) and (0, 1)?

Answer 1

`y = -3x + 1`

Explanation:

The `y` intercept form is `y = mx + b`

`m` = the slope of the line (think m mountain slope)
`b` = the `y` intercept ( think beginning the value of `y` when `x =0`

To find the slope use the equation

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

substituting the values for the points given

`(-5 - 1)/(2-0) = m` This gives

`-6/2 = -3 = m`

putting this value into the `y` intercept form gives

`y = -3x + b`

Substituting into the second equation gives

`1 = (-3) xx 0 + b` Solving this results in

`1 = b` substituting this value into the `y` intercept form gives

`y = -3x + 1`