16(x-y)²-25(x+y)²

16(x-y)²-25(x+y)²
16(x-y)²-25(x+y)²

16(x-y)²-25(x+y)²
16(x-y)²-25(x+y)²
= (4x-4y)²-(5x+5y)²
= ( 4x-4y + 5x+ 5y ) ( 4x- 4y - 5x - 5y)
= (5x + y )( -x - 9y)
= - (5x + y )( x + 9y)
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16(x-y)²-25(x+y)²
=[4(x-y)]^2-[5(x+y)]^2
=[4(x-y)+5(x+y)][4(x-y)-5(x+y)]
=-(9x+y)(x+9y)