SOLUTION: find two numbers whose sum is 20 and the difference of their square is 80

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Question 371842: find two numbers whose sum is 20 and the difference of their square is 80
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
1.A%2BB=20
.
.
I'm assuming you mean the difference of their squares.
2.A%5E2-B%5E2=80
From eq. 1,
A=20-B
A%5E2=400-40B%2BB%5E2
Substitute into eq. 2,
400-40B%2BB%5E2-B%5E2=80
400-40B=80
40B=320
highlight%28B=8%29
Then from eq. 1,
A=20-8
highlight%28A=12%29