# Thread: equations of a line

1. ## equations of a line

a. find the equation of a line that passes through point (-2,-1) and is parallel to line y=1.5x-5. write the equation of the line in slope intercept form.

b. find the equation of a line that passes through point (2,-4) and is PERPENDICILAR to the line y=2x+2. wite equation in spope intercept form.

2. Originally Posted by enyaz11
a. find the equation of a line that passes through point (-2,-1) and is parallel to line y=1.5x-5. write the equation of the line in slope intercept form.

b. find the equation of a line that passes through point (2,-4) and is PERPENDICILAR to the line y=2x+2. wite equation in spope intercept form.
Hi enyaz11,

(a) First, find the slope of the line that is going to be parallel to your line. The equation is in slope-intercept form:

$y=mx+b$

where m = slope. Therefore in your equation $y=1.5x-5$ the slope is 1.5.

Use this slope (since the line parallel to your line will have the same slope) and the point (-2, -1) to find the y-intercept (b) and determine the desired equation.

$y=mx+b$

$-1=1.5(-2)+b$

$b=2$

$\boxed{y=1.5x+2}$

(b) For this one, follow the same steps as (a) except the slope of the desired equation will be the negative reciprocal of the slope of the given equation. So, use $m=-\frac{1}{2}$ for your slope here.