SOLUTION: the sum of two numbers is 11 at most. Their difference is 21. What are these two numbers?

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Question 111203: the sum of two numbers is 11 at most. Their difference is 21. What are these two numbers?
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!
Let numbers be x and y, and assume that x+%3E+y
If the sum of two numbers is 11 at most, we have:
x+%2B+y+=+11

If their difference is 21 we have:

x+-+y+=+21
Now we have a system of equations:
Solve it by adding:
x+%2B+y+=+11
+ x+-+y+=+21.....add both equations and eliminate y

x+%2B++x+%2B+y+-%28y%29+=+11+%2B+21
2x++=+32…………………divide both sides by 2

2x%2F2++=+32%2F2…………………
x++=+16…………………
Now find y
x+%2B+y+=+11……………plug in x=16
16+%2B+y+=+11……………..move 16 to the right
+y+=+11+-+16
y+=+-+5

Check:
Plug in values for x and y in previous formulas:
x+%2B+y+=+11
16+-%285%29+=+11
11+=+11
another equation
x+-+y+=+21
x+-+%28-5%29+=+21
16+%2B+5+=+21
21+=+21