SOLUTION: Hello. How can I solve 3x-5y= 7 5x-2y=negative 1. I need to know a quick and easy way. I've been trying the add it straight down method but I'm a little

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Question 399643: Hello. How can I solve 3x-5y= 7
5x-2y=negative 1.
I need to know a quick and easy way. I've been trying the add it straight down method but I'm a little confused.
Please Help!

Found 3 solutions by checkley79, stanbon, Tatiana_Stebko:
Answer by checkley79(3341)   (Show Source):
You can put this solution on YOUR website!
In order to solve these 2 equation first you have to eliminate one of the unknowns (x or y).
3x-5y= 7 multiply this equation by 2
5x-2y=-1 multiply this equation by -5 & add.
6x-10y=14
-25x+10y=5
-------------
-19x=19
x=19/-19
x=-1 ans.
3*-1-5y=7
-3-5y=7
-5y=7+3
-5y=10
y=10/-5
y=-2
Proof:
5*-1-*-2=-1
-5+4=-1
-1=-1

Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website!
3x-5y= 7
5x-2y=-1
------
Multiply the 1st equation by 2.
Multiply the 2nd equation by 5.
-----------------------
6x-10y = 14
25x-10y =-5
------
Subtract 1st from 2nd and solve for "x":
19x = -19
x = -1
---
Solve for "y":
5x-2y = -1
5(-1)-2y = -1
2y =-4
y = -2
---
Cheers,
Stan H.
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Answer by Tatiana_Stebko(1539)   (Show Source):
You can put this solution on YOUR website!
3x-5y= 7
5x-2y=-1
better use here the add it straight down method.
Multiply first equation at 2, and second equation at (-5)
6x-10y=14
-25x+10y=5
In this way we have now (-10y) in the first equation, and 10y in the second.
Add the first equation to the second
6x-10y=14
(-25x+10y)+(6x-10y)=5+14
.
6x-10y=14
-19x=19, then
.
put in the first equation 3x-5y= 7

Answer (-1;-2)