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Question 705877: SOLVE STEP BY STEP THANK YOU:)
1) x+y=5
3x-y=7
2) 2x+y=3
-2x+5y=-9
3) 3x+5y=0
2x-5y=-25
4) -4x-y=-6
4x+3y=18
5) 2x-y=-5
-2x-5y=11
6) 8=4x-3y
17=x+3y
7) -6=3x+y
10=-5x-y
8) 3x+8y=-1
-3x+y=-17
9) x+2y=15
5x=2y+3
10) 7x-y=12
-3y=7x+8
11) y=3x+13
2x=y-9
12) 4x+12=-7y
-y+12=4x
13) 3x+2y=6
y=x+3
14) -x+4y=-4
y=x-1
15) -300x-125y=1350
y+2=8
16) 2x-y=6
1/6x-1/12y=1/2
17)4x+4y=5
x-4y=-5/2
18) -2x+y=-6
6x-13y=-12
19) 2(x+2y)=12
-6x=5y-8
20) 5x-2y=-25
10x=3(y-10)
21) 5(3x-y)=10
4y=7x-3
22) 2x=-3(y+3)
3x-4y=-22
23) 2x-5=7
4=3y+1
24) -2=4-2y
7x-5=-5
Answer by Alan3354(69443)   (Show Source):
You can put this solution on YOUR website! SOLVE STEP BY STEP THANK YOU:)
1) x+y=5
3x-y=7
---------- Add
That method is elimination.
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2) 2x+y=3
-2x+5y=-9
Same as #1
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3) 3x+5y=0
2x-5y=-25
Same as #1
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4) -4x-y=-6
4x+3y=18
5) 2x-y=-5
-2x-5y=11
6) 8=4x-3y
17=x+3y
7) -6=3x+y
10=-5x-y
8) 3x+8y=-1
-3x+y=-17
4 thru 8 same as #1
================================
9) x+2y=15
5x=2y+3 --> 5x-2y = 3
Then same as #1
==============================
10) 7x-y=12
-3y=7x+8
Rearrange, then ...
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11) y=3x+13
2x=y-9
You can do it like #1, elimination, or you can use substitution.
Since y is given in the 1st eqn, sub for it in the 2nd.
2x = y - 9
2x = 3x+13 - 9
Then solve for x, etc
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12) 4x+12=-7y
-y+12=4x
Rearrange, then subtract.
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13) 3x+2y=6
y=x+3
Sub for y in the 1st eqn
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14) -x+4y=-4
y=x-1
Same as #13
====================
15) -300x-125y=1350
y+2=8
No x in the 2nd eqn --> y = 6
==============================
16) 2x-y=6
1/6x-1/12y=1/2
Multiply eqn 2 by 12 to eliminate fractions.
Then the 2 equations are the same.
--> dependent, and infinite # of solutions.
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17)4x+4y=5
x-4y=-5/2
--------------- Add
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18) -2x+y=-6
6x-13y=-12
Multiply the 1st eqn by 3, then add
============================
19) 2(x+2y)=12 --> x + 2y = 6
-6x=5y-8
Solve eqn 1 for x, sub for x in eqn 2
===========================
*****************************************
Pick the best method for the rest.
20) 5x-2y=-25
10x=3(y-10)
21) 5(3x-y)=10
4y=7x-3
22) 2x=-3(y+3)
3x-4y=-22
23) 2x-5=7
4=3y+1
24) -2=4-2y
7x-5=-5
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