 i need help please! - XP Math - Forums Sign Up FREE! | Sign In | Classroom Setup | Common Core Alignment  XP Math - Forums i need help please! 03-30-2011 #1 kimsoohanmoo   Join Date: Mar 2011 Posts: 1 i need help please! Find the relation ship between the set of ordered pairs (-3, 7), (-1, 3), (3, -5), (4,-7) please help me with this Ive been stuck on this for a very, very long time. Im not looking to graph them I mean like (example) (4, 2), ...etc the relationship between them is that y is the square root of x. I know for the question I asked it isnt multiplication or division or the square root so it must be some sort of equation right. Ive been working on this for two days.............    03-31-2011 #2 karemma13   Join Date: Oct 2010 Posts: 4 Hey The relationship between the all the set of order pairs is -2. My teacher helped me though. How I got it: I took 2 of each of the order pairs. (-3,7) & (4,-7) Note: There suppose to be fractions. 7- -7 7+7 14 Divide! ____ = ____= ___=-2 -3-4 -3-4 -7 Let me explain. You put the second Y on top then the first Y. After you do that you put the second X at the bottom then put the first X at the bottom.(X1,Y1) & (X2,Y2). After that you do your interger rules. Then you add 7+7=14, then you add -3+-4=-2. Then you divide 14/-7=-2. You can do that with either 2 order pairs you want.   03-31-2011 #3 keairra13   Join Date: Oct 2010 Posts: 7 Help Solved!! Well in order to find the relation you have to find the slope for each ordered pairs. (-3,7) (-1,3) (3,-5) (4,-7) NOTE THIS IS ONLY IF YOU DON'T KNOW HOW TO FIND THE SLOPE So you first take the first ordered pairs (3,-5) and (4,-7). Then you set them up like this: -7- -5 = -2 ____ ___ 3 - 4 = 1 Then afterwards you would divide the denominator by the numerator to get your slope and that should be -2. Now you should know that the slope rules (Y2 - Y1) (X2 - X1) Thats how you get your slope. you do that for the other two ordered pairs and you should also get -2. So since you got -2 for both of you slopes then you found the relation.   04-01-2011   #4
MAS1   Join Date: Dec 2008
Posts: 249 Quote:
 Originally Posted by kimsoohanmoo Find the relation ship between the set of ordered pairs (-3, 7), (-1, 3), (3, -5), (4,-7) please help me with this Ive been stuck on this for a very, very long time. Im not looking to graph them I mean like (example) (4, 2), ...etc the relationship between them is that y is the square root of x. I know for the question I asked it isnt multiplication or division or the square root so it must be some sort of equation right. Ive been working on this for two days............. If you graph them you can see these coordinates form a line.

To check that it is a linear function look to see that there is a constant rate of change (slope) between the points.

(-3, 7), (-1, 3): m = (3 - 7) / (-1 - -3) = -4 / 2 = -2

(-1, 3), (3, -5): m = (-5 - 3) / (3 - -1) = -8 / 4 = -2

(3, -5), (4, -7): m = (-7 - -5) / (4 - 3) = -2 / 1 = -2

So yes, there is a constant rate of change between the points.
To find the equation try using point-slope form of a line.

First pick a point, say (4, -7). Point-slope form is y - y1 = m(x - x1).

Then y - -7 = -2(x - 4)
y + 7 = -2x + 8
y = -2x + 1
Hope this helps.   04-01-2011 #5 <3MorganLovesCassidyyy<3   Join Date: Apr 2011 Posts: 1 Oh this is helpful:d   04-01-2011 #6 kaysie!!!:)   Join Date: Apr 2011 Posts: 1 Hey thanks!!! this is awesome    04-02-2011   #7
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 Originally Posted by kimsoohanmoo Find the relation ship between the set of ordered pairs (-3, 7), (-1, 3), (3, -5), (4,-7) please help me with this Ive been stuck on this for a very, very long time. Im not looking to graph them I mean like (example) (4, 2), ...etc the relationship between them is that y is the square root of x. I know for the question I asked it isnt multiplication or division or the square root so it must be some sort of equation right. Ive been working on this for two days............. y = -2x + 1   04-08-2011 #8 EthanS.   Join Date: Feb 2011 Posts: 7 Help me with post HOW DO U MAKE A NEW POST???????????????    :ic on_rolleyes:       :icon_cryin g:   05-25-2011 #9 Mz.Lachon'Tae_gets_\$   Join Date: Mar 2011 Posts: 3 I tink dey -2 n add 3  Thread Tools Show Printable Version Email this Page Display Modes Linear Mode Switch to Hybrid Mode Switch to Threaded Mode Posting Rules You may not post new threads You may not post replies You may not post attachments You may not edit your posts BB code is On Smilies are On [IMG] code is On HTML code is Off Forum Rules
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