Question

 

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

b)(x+y)^3-2y^3-(x-y)^3

c)(x-y)^2-2×(y-x)×(x+y)+(x+y)^2

Answer 1

2y^2

 

Answer 2

a,(2x-y)²-(2x+y)²

=(2x²-2.2xy+y²)-(2x²+2.2xy+y²)

=2x²-4xy+y²-2x²-4xy-y²

=-8xy

Answer 3

b,(x+y)³-2y³-(x-y)³

=(x³+3x²y+3xy²+y³)-2y³-(x³-3x²y+3xy²-y³)

=x³+3x²y+3xy²+y³-2y³-x³+3x²y-3xy²y³

=6x²y

Answer 4

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