3x = 2y - 4
6x - 4y = -4
What is x and y?
2006-10-02 17:08:51 · 5 answers · asked by nr91326 3 in Education & Reference ➔ Homework Help
I'm going to trust that you really don't get it and are not using this question to get away with not doing your homework.
First, you have to decide which equation you want to start with. I chose the second one for no particular reason. I rearranged the equation by addition and division so that it reads: 1.5x + 1 = y.
Now, it is all plug and chug.
3x = 2(1.5x + 1) - 4
3x = 3x + 2 - 4
3x = 3x - 2
0 = -2
This means that the solution does not exist. The two lines do not cross each other at any point.
This can be further proved by manipulating both equations so that they are in slope-intercept [y = mx +b] form. For the first equation, you get y = 1.5x + 2 and for the second equation, you get y = 1.5x + 1. Because the slopes of both lines are equal, you can say that the lines are parallel, and parallel lines do not intersect. Ever.
Okay, so I have said all of this, but I would suggest that yuo double check my math because I did it in my head [and I am not good at mental math >.<]
I hope that this made sense to you and that you understand it now! :]
2006-10-02 17:25:46 · answer #1 · answered by mega_roony 2 · 0⤊ 0⤋
Since you have x isolated in the first equation, divide all coefficients by 3...
x = (2y-4)/3
Substitute this x into the second equation...
6[(2y-4)/3] - 4y = -4
Cancel the 6 with the denominator 3....
2(2y-4) - 4y = -4
Distributive property...
4y - 8 - 4y = -4
Subtract...
-8 = -4
Since all variables have been eliminated and this is false, your system has NO SOLUTION.
2006-10-03 00:21:17 · answer #2 · answered by Michael W 3 · 0⤊ 0⤋
3x=2y-4
x=(2y-4)/3
now subsitute this value of x in the second statement
6(2y-4)/3-4y=-4
2(2y-4)-4y=-4
4y-8-4y=-4
-8=-4
which cant b true so this has no sulution
2006-10-03 07:05:10 · answer #3 · answered by hmmm 3 · 0⤊ 0⤋
double the first and subtract the second
6x-4y=-8
subtract
6x-4y=-4
doesn't work
did you type it in correctly?
j
2006-10-03 00:16:12 · answer #4 · answered by odu83 7 · 0⤊ 0⤋
did it myself, NO SOLUTION!
2006-10-03 00:41:27 · answer #5 · answered by slushie 2 · 0⤊ 0⤋