Question

a ) \(\left(x-y\right)^2-\left(x+y\right)^2\)

Answer 1

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\(\left(x-y\right)^2-\left(x+y\right)^2\)

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

\(=-4xy\)

Answer 2

\(\left(x-y\right)^2-\left(x+y\right)^2\)

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

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

\(=2.\left(x^2+y^2\right)\)

Answer 3

\(\left(x-y\right)^2-\left(x+y\right)^2\)

\(=\left(x-y-x-y\right)\left(x-y+x+y\right)\)

\(=-2y.2x\)

\(=2\left(x-y\right)\)