SOLUTION: One number is seven times another. If their difference is 18, what are the numbers?

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Question 503478: One number is seven times another. If their difference is 18, what are the numbers?
Answer by oberobic(2304) About Me  (Show Source):
You can put this solution on YOUR website!
x = one number
y = another
x = 7y
x-y =18
.
substitute x=7y
7y-y = 18
6y = 18
y = 3
.
substitute y=3
x = 7y
x = 7(3)
x = 21
.
Always check your answer.
Is the difference = 18?
21 -3 = 18.
Correct.
And of course, we know 21 = 3*7
.
The two numbers are 3 and 21.
.
Done