运用平方差公式计算(2x-1)(2x+1) (1/2a-2b)(1/2a+2b)(5m+3n)(3n-5m)(-x+y)(-x-y)101×99 9.8×10.2

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运用平方差公式计算(2x-1)(2x+1) (1/2a-2b)(1/2a+2b)(5m+3n)(3n-5m)(-x+y)(-x-y)101×99 9.8×10.2

运用平方差公式计算(2x-1)(2x+1) (1/2a-2b)(1/2a+2b)(5m+3n)(3n-5m)(-x+y)(-x-y)101×99 9.8×10.2
运用平方差公式计算
(2x-1)(2x+1)
(1/2a-2b)(1/2a+2b)
(5m+3n)(3n-5m)
(-x+y)(-x-y)
101×99
9.8×10.2

运用平方差公式计算(2x-1)(2x+1) (1/2a-2b)(1/2a+2b)(5m+3n)(3n-5m)(-x+y)(-x-y)101×99 9.8×10.2
(2x-1)(2x+1)
=(2x)²-1
=4x²-1
(1/2a-2b)(1/2a+2b)
=(1/2a)²-(2b)²
=1/4a²-4b²
(5m+3n)(3n-5m)
=(3n)²-(5m)²
=9n²-25m²
(-x+y)(-x-y)
=(-x)²-y²
=x²-y²
101×99
=(100+1)×(100-1)
=100²-1
=10000-1
=9999
9.8×10.2
=(10-0.2)×(10+0.2)
=10²-0.2²
=100-0.04
=99.96