Question 819077: What would the ordered pair be for x-3y=2 and 3x-7y=4. Here is the work that I have done so far. x-3y=2 Then I got y by itself by subtracting x on both sides so I got -3y=-x+2. Then I divided -3y by itself on both sides. So I got y=1/3x-2/3. Then I plugged y into the equation x-3y=2. Once I plugged it in I got x-3(1/3x-2/3)=2. Once I solved that I got x-x-2=2. Then I added 2 on each side to get x-x=4 Then I solved that to get 0x=4 and I didn't know what I did wrong. So I double checked myself to see if I got a different answer. This is what I did; I plugged y into the equation 3x-7y=4 and got 3x-7(1/3x-2/3)=4. Then I distributed and got 3x-(7/3x-14/3=4. After this I got lost and didn't know what to do. If you can help that'd be great! Thanks!
Found 2 solutions by ankor@dixie-net.com, MathTherapy:
Answer by ankor@dixie-net.com(22740)   (Show Source):
You can put this solution on YOUR website! x - 3y = 2
3x- 7y = 4
:
Just use elimination here multiply the 1st equation by 3
3x - 9y = 6
3x - 7y = 4
------------Subtraction eliminates x, find y
0 - 2y = 2
y = 2/-2
y = -1
:
Use the 1st equation to find x, replace y with -1
x - 3(-1) = 2
x + 3 = 2
x = 2 - 3
x = -1
:
Check solutions in the 2nd equation replace x and y with -1
3(-1) - 7(-1) = 4
-3 + 7 = 4, confirms our solution of x=-1,y=-1
Answer by MathTherapy(10552)  (Show Source):
You can put this solution on YOUR website!
What would the ordered pair be for x-3y=2 and 3x-7y=4. Here is the work that I have done so far. x-3y=2 Then I got y by itself by subtracting x on both sides so I got -3y=-x+2. Then I divided -3y by itself on both sides. So I got y=1/3x-2/3. Then I plugged y into the equation x-3y=2. Once I plugged it in I got x-3(1/3x-2/3)=2. Once I solved that I got x-x-2=2. Then I added 2 on each side to get x-x=4 Then I solved that to get 0x=4 and I didn't know what I did wrong. So I double checked myself to see if I got a different answer. This is what I did; I plugged y into the equation 3x-7y=4 and got 3x-7(1/3x-2/3)=4. Then I distributed and got 3x-(7/3x-14/3=4. After this I got lost and didn't know what to do. If you can help that'd be great! Thanks!
x - 3y = 2 ----- eq (i)
3x - 7y = 4 ----- eq (ii)
Seems as though you want to solve this using substitution.
Well, you don't have to go through all of that. You can just simply solve eq (i) for x, and substitute that into
eq (ii). In other words: x - 3y = 2 becomes: x = 2 + 3y, or x = 3y + 2, which can be substituted into eq (ii) to
determine the value of y. Then substitute this y-value into any of the two equations to determine the value of x.
You can do the check!!
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