Question 646225
 one of the numbers is twice the other number and the sum of the number is 39. What are the numbers?
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Equations:
x = 2y
x + y = 39
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Substitute for "x" and solve for "y":
2y + y = 39
3y = 39
y = 13
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Solve for "x":
x = 2y
x = 26
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Cheers,
Stan H.