SOLUTION: The average of 2 numbers is 15 and four times the difference between them is 4o. Find the numbers.

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Question 151016: The average of 2 numbers is 15 and four times the difference between them is 4o. Find the numbers.
Answer by jojo14344(1513) About Me  (Show Source):
You can put this solution on YOUR website!
Let "x"= 1st #, & "y"= 2nd #
1st condition: Average of 2 numbers is 15,
%28x%2By%29%2F2=15
2nd condition: 4 times the diff. is 40,
4%28x-y%29=40
.
In 1st condtn. we get x%2By=30 --> REMEMBER THIS EQ'N,
x=30-y and substitute this "x" value in 2nd condtn.
4%2830-y-y%29=40
120-4y-4y=40
120-40=4y%2B4y ----> 80=8y
y=10, and REMEMBER EQ'N x%2B10=30 ---> x=30-10 --> x=20
To check,
Go back 1st condtn.; %2820%2B10%29%2F2=15 ----> 15=15
For 2nd condtn.; 4%2820-10%29=40 ------> 40=40
Thank you
Jojo