SOLUTION: half the sum of two numbers is 20 and three times their differences is 18. find the numbers.

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Question 479997: half the sum of two numbers is 20 and three times their differences is 18. find the numbers.
Answer by Tatiana_Stebko(1539) About Me  (Show Source):
You can put this solution on YOUR website!
Let x and y are numbers
Half of the sum is %28x%2By%29%2F2 is 20, so %28x%2By%29%2F2=20
Three times their difference 3%28x-y%29=18
The system of the equations
system%28%28x%2By%29%2F2=20%2C+3%28x-y%29=18%29 multiply the first equation by 2, divide the second equation by 3
system%28x%2By=40%2C+x-y=6%29 add the second equation to the first
2x=46
x=46%2F2
x=23 is the first number
23%2By=40
y=40-23
y=17 is the second number