How do you do this I know how to do it whan it says things like through (4, 5), slope = 2 but not this :(
3) through: (-2, -1) and (-1, 1)
4) through: (4, 0) and (-1, 5)
5) through: (0, -2) and (4, 0)
6) through: (5, 3) and (4, -1)
7) through: (-3, 1) and (0, -5)
8) through: (-5, 2) and (-2, -4)
Kerrie
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First of all, Slope intercept form is Y=MX+B Where, M is slope and B is a constant.
You need to find the slope of each of your pairs of numbers. That's done by
Y2-Y1 / X2-X1.
Now you need to find B, to finish the equation. You do this by choosing a point and substituting them in and working the equation out until you get B= (an integer)
I will do one for you as an example. "3) through: (-2, -1) and (-1, 1)"
Find the slope of the line. Y2-Y1 is the numerator. 1-(-1)=2 Now for the denominator, X2-X1. -1-(-2)=1
Together it looks like,
1+1 / -1+2
Slope equals 2.
So far in writing our equation, we have Y=2X+B
We need to solve for B. I picked point 'A,' (-2, -1), to substitute in for X and Y.
So,
-1=2(-2)+B Multiply the 2 and -2.
-1=-4+B Add 4 to both sides.
3=B
Now put the whole equation together!
Y=2X+3 <--That is the answer to finding the slope intercept form of the line through given points, (-2, -1) and (-1, 1)
I hope this helped and I know you can do the rest on your own! :)
MoonRose
First find the slope using the slope formula (y2 - y1)/(x2 - x1), where (x2, y2) and (x1, y1) are points on the line.
3.) Slope = (y2 - y1)/(x2 - x1) = (-1 - 1)/(-2 - -1) = -2/(-2 + 1) = -2/-1 = 2
Now that you know the slope, you can use either of the points (it doesn't matter which one) to find the equation like you usually do.
4.) Slope = (0 - 5)/(4 - -1) = -5/(4 + 1) = -5/5 = -1
5.) Slope = (-2 - 0)/(0 - 4) = -2/-4 = 1/2
6.) Slope = (3 - -1)/(5 - 4) = (3 + 1)/1 = 4/1 = 4
Try the others yourself.
Anonymous
slope intercrpt form is 'y = mx + b' so we need to find the m and the b. the m is the slope. and the b is the y-intercpt. so if the question is throught (-2,-1) and (-1,1) to find the slope u use this formula
(y2 - y1) / (x2 - x1) the 2 stands for the 2nd point given, so the (-1,1)
and the 1 stands for the first point, so the (-2,-1) so yu would plug in -1 for y2 and 1 for y1
(-1-1) / (x2-x1) and same thing with the x's so it would be ((-1)-1) / (-1-(-2) simplify the parentcys first so you get (-2) / ( 1) (you get 1 becuase if u minus a negative it turns positive)
so the ur slope is -2/1 that is your m
so plug in all you know y=(-2/1)x+b, so then you have your slope and points so, then you can slove for b which u said above that you can do
Sayy Ohh
Find the slope with the points using the formula
y2-y1/x2-x1
so the first one would be 1-(-1) over -1-(-2) so its 2/1 or other words
now do the rest with what you know
Suzie
slope intercept is y=mx+b
first find m, find this by plugging the two points into m=(y2-y1)/(x2-x1)
for the first.
m=(1+1)/(-1+2)
m=2/1
m=2
now you have the equation y=2x+b so you need to find b, do this by plugging one of the points into the equation and solving for b
1=2(-1)+b
1=-2+b
3=b
your equation for the first is y=2x+3, do the same for the rest.