Question

6(x+y)的平方-2(x-y)(x+y)

Answer 1

解
6(x+y)²-2(x-y)(x+y)
=2(x+y)[3(x+y)-(x-y)]
=2(x+y)(2x+4y)
=4(x+y)(x+2y)

Answer 2

6(x+y)²-2(x-y)(x+y)
=6(x²+2xy+y²)-2(x²-y²)
=6x²+12xy+6y²-2x²+2y²
=4x²+12xy+8y²
=4(x²+3xy+2y²)
=4(x+y)(x+2y)