Question 259887
solve by the substitution method and then two ordered pairs! 
9x-9y=-9
3x+13=y
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Simplify the 1st equation:
x - y = -1
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Substitute for "y" in this equation and solve for "x":
x - (3x+13) = -1
x - 3x - 13 = -1
-2x = 12
x = -6
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Substitute into x-y = -1 to solve for "y":
-6 - y = -1
y = -5
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Solution:
x = -6, y = -5
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9x-9y=-9
3x+13=y
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x-y = -1
3x+13 = y
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y = x+1
y = 3x+13
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{{{graph(400,300,-10,10,-10,30,x+1,3x+13)}}}
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Cheers,
Stan H.