SOLUTION: x^2+y^2=48 (x-y)=4 Find the value of xy

Question 658834: x^2+y^2=48
(x-y)=4
Find the value of xy
Found 2 solutions by Alan3354, kevwill:
Answer by Alan3354(69443) (Show Source): You can put this solution on YOUR website!
x^2+y^2=48
(x-y)=4
Find the value of xy
---------
x = y+4
(y+4)^2 + y^2 = 48
etc
Answer by kevwill(135) (Show Source): You can put this solution on YOUR website!
From we know
Substituting into the first equation gives

Expanding:

Combining like terms:

Subtracting 48 from both sides:

Dividing both sides by 2:

This can be solved using the quadratic equation with a=1, b=-4, and c=-16

So x can have the values or
For we have

Checking:

And

For we have
Checking:

And

So for either value of x, x*y = 16

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