Question 1106731: I am attempting to help my daughter with her algebra homework. It has been years since I have done algebra. I am having a problem with what I believe is a linear equation we have to graph.
3y=2x-2
I also have problems that Id like to see if I have gotten correct
x-2y=15 I have if x=0 then y=7.5
5y=-2x-49 I have (0,9.8) and (-3, -8.6)
y=-5x-19 I have (0,19) and (2,-9)
4y=x-13 I have (0,-3.25) and (-2, -3.75)
Can you help with the first one and identify any I have wrong so I can re work them. Thank you
Answer by Alan3354(69443)   (Show Source):
You can put this solution on YOUR website! I am attempting to help my daughter with her algebra homework. It has been years since I have done algebra. I am having a problem with what I believe is a linear equation we have to graph.
3y=2x-2
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It is linear, meaning the graph is a line, a straight line.
2 points are needed.
3y = 2x - 2
The simplest way to find 2 points is to find y when x=0, and x when y=0.
3y = 2x - 2
3y = 2*0 - 2
3y = -2
y = -2/3
--> the point (0,-2/3)
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3y = 2x - 2
3*0 = 2x - 2
0 = 2x - 2
2x= 2
x = 1
--> the point (1,0)
Plot the 2 points, draw a line thru them.
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It's a good idea to calculate and plot a 3rd point. It makes any mistakes obvious if the 3 points are not colinear.
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I also have problems that Id like to see if I have gotten correct
x-2y=15 I have if x=0 then y=7.5
0-2y = 15
y = -7.5
---------
5y=-2x-49 I have (0,9.8) and (-3,-8.6)
5y = -49
y = -9.8, not +9.8
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At x = -3:
5y = 6 - 49 = -43
y = -8.6
======================
y=-5x-19 I have (0,19) and (2,-9)
At x = 0:
y = -19 ---- wrong sign again --> (0,-19)
At x = 2:
y = -5*2 - 19 = -29 --> (2,-29)
====================
4y=x-13 I have (0,-3.25) and (-2,-3.75)
(0.-3.25) is correct
---
At x = -2:
4y = -2-13 = -15
y = -3.75 also correct
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A useful tool is the FREE graph software at
www.padowan.dk
You can enter the equations and see if your calculated points are on the line.
Use F6 to enter the equations as they're given. Pick your color.
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