Question

If x - y =5, x + y =1, then x^2 - y^2= ??

+explanation please and thanks​

Answer 1

Answer: 5

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Step-by-step explanation:

Apply the difference of squares rule

x^2 - y^2 = (x-y)(x+y)

x^2 - y^2 = (5)(1)

x^2 - y^2 = 5

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Alternatively, you can solve the system

`\begin{cases}x-y=5\\x+y = 1\end{cases}`

for x and y to get (x,y) = (3,-2).

Then compute x^2-y^2 = 3^2-(-2)^2 = 9-4 = 5