SOLUTION: two numbers differ by seven. If their sum is sixty-five, what are the numbers?

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Question 124887: two numbers differ by seven. If their sum is sixty-five, what are the numbers?
Answer by iluvbuilding429(41) About Me  (Show Source):
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two numbers differ by seven. If their sum is sixty-five, what are the numbers?


You know that:
65=x%2By


You also know:
y=x-7
Substitute this for y in your equation and you get:
65=x%2Bx-7


Add:
65=2x-7


Add 7 to both sides:
72=2x


Divide both sides by 2:
36=x


Now you know that your first number is 36. To find the second number, use y=x-7.
y=36-7


Subtract:
y=29


So now you know that your first number is 36, and your second number is 29. To check, add the two together, and it should equal 65.
65=36%2B29


Add:
65=65