Question

A line passes through ( - 1, - 1) and ( - 3, 5).

What is the equation of the line in slope-intercept form?

Answer 1

y= -3x-4.

Explanation:

1) the slope-interception form is:

y=slope*x+i, where i - interception;

2) using the given two points it is possible to calculate the slope:

`slope=(5+1)/(-3+1)=-3;`

then the required equation has the form:

y=-3x+i;

3) in order to calculate the 'i', it is enough to substitute the coordinates of the one point into this form of the required equation:

-1=-3*(-1)+i; ⇒ i=-4.

4) finally, the required equation is:

y=-3x-4.

P.S. the suggested way is not the shortest one.