SOLUTION: The sum of three numbers is thirty. The second number is twice the first number, and the third number is 5 less than the second number. Find the three numbers.

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Question 644094: The sum of three numbers is thirty. The second number is twice the first number, and the third number is 5 less than the second number. Find the three numbers.
Answer by nerdybill(7384) About Me  (Show Source):
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The sum of three numbers is thirty. The second number is twice the first number, and the third number is 5 less than the second number. Find the three numbers.
.
Let x = first number
then from "The second number is twice the first number"
2x = second number
and from "third number is 5 less than the second number"
2x-5 = third number
.
we get our equation from "sum of three numbers is thirty"
x + 2x + 2x-5 = 30
5x-5 = 30
5x = 35
x = 7 (first number)
.
second number:
2x = 2(7) = 14
.
third number:
2x-5 = 2(7)-5 = 14-5 = 9