SOLUTION: The sum of two numbers is 20. The difference of their squares is 120. What are the numbers?

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Question 170750This question is from textbook algebra and trigonometry
: The sum of two numbers is 20. The difference of their squares is 120. What are the numbers? This question is from textbook algebra and trigonometry

Answer by checkley77(12844) About Me  (Show Source):
You can put this solution on YOUR website!
X+Y=20 OR X=20-Y
X^2-Y^2=120
(20-Y)^2-Y^2=120
400-40Y+Y^2=120
-40Y=120-400
-40Y=-280
Y=-280/-40
Y=7 ans.
X+7=20
X=20-7
X=13 ans.
Proof:
13^2-7^2=120
169-49=120
120=120