SOLUTION: I am still not getting this can anyone help me with this? solve by elimination method -7x+5y=-20 -3x-2y=8 I know that I am to multiply the first equation by 2 and the second

Algebra ->  Equations -> SOLUTION: I am still not getting this can anyone help me with this? solve by elimination method -7x+5y=-20 -3x-2y=8 I know that I am to multiply the first equation by 2 and the second       Log On


   

Question 459179: I am still not getting this can anyone help me with this?
solve by elimination method
-7x+5y=-20
-3x-2y=8
I know that I am to multiply the first equation by 2 and the second equation by 5 which would give me -14x+10y=-4 and -15x-10y=40. Then I am to add them which would give me -29x=36 but I don't know where to go from there. Can someone help me please, thank you so much
Answer by math-vortex(648) About Me  (Show Source):
You can put this solution on YOUR website!
I always appreciate when a student tells us what they've tried so far. Good work!
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I see a small arithmetic error in your first equation. Multiplying the right side by 2 gives (2)(-20)=-40 so your new equation would be -14x+10x=-40.
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Add the two equations,
-14x%2B10y=-40
-15x-10y=+40
to give,
-29x=0
Divide both sides by -29.
x=0
Now, substitute 0 for x into one of the original equations to find the y-value. It doesn't matter which one.
-7x%2B5y=-20
-7%280%29%2B5y=-20
5y=-20
y=-4
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So, the solution to your system of equations is the order pair (0,-4). It's always a good idea to check your work for possible errors.
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CHECK:
-7x%2B5y=-20
-7%280%29%2B5%28-4%29=-20
0-20=20
-20=-20
Good. Now check the other equation.
-3x-2y=8
-%280%29-2%28-4%29=8
8=8
Winner, winner, chicken dinner! (o: