Question 404787: x+y=19
x-y=-7 how do u do this by elimination
Found 3 solutions by stanbon, richard1234, keksjr:
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! x+y=19
x-y=-7
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Add and solve for "x":
2x = 12
x = 6
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Solve for "y":
x + y = 19
6 + y = 19
y = 13
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Cheers,
Stan H.
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Answer by richard1234(7193)  (Show Source):
You can put this solution on YOUR website! Add the two equations to get 2x = 12 --> x = 6. Replacing x = 6 to either equation (preferably the first one because it's easier) we get y = 13, so our solution (x, y) is (6, 13).
Answer by keksjr(7)  (Show Source):
You can put this solution on YOUR website! taking x+y=19 to be eqtn I and
x-y=-7 to be eqtn II
if x and y have coefficients, you will have to choose from the two unknown x and y, which one to eliminate first by using the coefficient in either eqtn I or eqtn II to multiple all through what's on eqtn II and same to eqtn I respectively.
But since there is no coefficient there on the two variables, the add x to eliminate y: By doing so, you have;
add "x and x = 2x" , "+y and -y = 0", "19 and -7 = 12"
2x+0=12, 2x=12, x=6.
substitute "x" in any of the 2 above eqtn but lets use eqtn I to find y:
x+y=19
6+y=19
y=19-6
y=13
(x,y) (6,13)
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