计算:(1)(2m+3n)(2m-3n) (2) (-3a-1/2b)(-3a+1/2b) (3) (-4x+y)(y+4x)

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计算:(1)(2m+3n)(2m-3n)(2)(-3a-1/2b)(-3a+1/2b)(3)(-4x+y)(y+4x)计算:(1)(2m+3n)(2m-3n)(2)(-3a-1/2b)(-3a+1/2

计算:(1)(2m+3n)(2m-3n) (2) (-3a-1/2b)(-3a+1/2b) (3) (-4x+y)(y+4x)
计算:(1)(2m+3n)(2m-3n) (2) (-3a-1/2b)(-3a+1/2b) (3) (-4x+y)(y+4x)

计算:(1)(2m+3n)(2m-3n) (2) (-3a-1/2b)(-3a+1/2b) (3) (-4x+y)(y+4x)
都是平方差
原式=4m²-9n²
原式=(-3a)²-(1/2b)²
=9a²-1/4b²
原式=(y-4x)(y+4x)
=y²-16x²