Question 282189
Substitution is done by...well...substitution.
You use one equation to find a value for 'x'.
Then you substitute that into the other equation.
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5x + 8y = 18
x = 6 -2y
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So the second equation is a easy substitution candidate into the first equation.
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5(6-2y) +8y = 18
30 -10y +8y = 18
30 -2y = 18
-2y = -12
y = 6
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Now substitute back to find 'x'.
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x = 6 -2(y)
x = 6 -2(6)
x = 6 -12
x = -6
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Check by plugging these values into the other equation to ensure they're right.
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5x + 8y = 18
5(-6) + 8(6) = 18??
-30 +48 = 18
Correct!
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Answer:
x = -6
y = 6
.
Done.