Question

2004.05*1997.05-2001.05*1999.05的简便运算

Answer 1

2004.05×1997.05－2001.05×1999.05
=(2001.05+3)×1997.05－2001.05×1999.05
=2001.05x1997.05+3x1997.05-2001.05x1999.05
=2001.05x(1997.05-1999.05)+3x(2000-2.95)
=2001.05x-2+3x2000-2.95x3
=-4002.1+6000-(3-0.05)x3
=6000-4000-2.1-9+0.15
=2000.15-11.1
=1989.05

Answer 2

2004.05×1997.05－2001.05×1999.05
=(2001.05+3)×1997.05－2001.05×1999.05
=2001.05x1997.05+3x1997.05-2001.05x1999.05
=2001.05x(1997.05-1999.05)+3x(2000-2.95)
=2001.05x-2+3x2000-2.95x3
=-4002.1+6000-(3-0.05)x3
=6000-4000-2.1-9+0.15
=2000.15-11.1
=1989.05

Answer 3

1989.05

• 解析：

　　2004.05×1997.05－2001.05×1999.05

　　=(2000.55+3.5)×(2000.55-3.5)-(2000.05+1)×(2000.05-1)

　　=2000.55²-3.5²-(2000.05²-1)

　　=2000.55²-2000.05²+1-3.5²

　　=(2000.55+2000.05)(2000.55-2000.05)+1-12.25

　　=4000.6×0.5-11.25

　　=2000.3-11.25

　　=1989.05

Answer 4

原式=2004.05x1997.05-2001.05x1997.05-2001.05x2
=3x1997.05-2001.05x2
=3x1997.05-2x1997.05-2x4
=1997.05-8
=1989.05

Answer 5

2004.05×1997.05－2001.05×1999.05
=(2001.05+3)×1997.05－2001.05×1999.05
=2001.05x1997.05+3x1997.05-2001.05x1999.05
=2001.05x(1997.05-1999.05)+3x(2000-2.95)
=2001.05x-2+3x2000-2.95x3
=-4002.1+6000-(3-0.05)x3
=6000-4000-2.1-9+0.15
=2000.15-11.1
=1989.05