1.9k views
3 votes
Find the slope of each line.

1 Answer

7 votes

Can you please provide the lines we need to work on?

Upload ONLY one image, please

Recall that in order to find the equation of a line, we need at least TWO points on the plane. So we are going to use the two points that are marked with blue dots:

the oe more towards the left and down is the point (-3, -3) and the point to the right of the y-axis is (1, -1).

So we use them in the formula for the slope:

slope = (y2 - y1) / (x2 - x1)

in our case:

slope = (-3 - (-1)) / (-3 -1) = (-3+1) / (-4) = -2 / (-4) = 1/2

Then 1/2 is our slope.

So we use this slope "m" = 1/2 in the general slope-intercept form of a line:

y = m x + b

and replace m with "1/2":

y = (1/2) x + b

all we need now is the value of "b" (called the y-intercept), and for that we use either point in the equation above, for example point (1, -1), to determine its value:

-1 = (1/2) (1) + b

-1 = (1/2) + b

subtract 1/2 from both sides to isolate "b"

- 1 - 1/2 = b

then b = - 3/2

and now we can write the equation of this line in slope intercept formas:

y = (1/2) x - 3/2

Find the slope of each line.-example-1
User Kamilla
by
4.3k points