1999+1998-1997-1996+1995+1994-1993-1992+.-1

√18除以√8
=√(18÷8)
=√(9/4)
=3/2
√0.4乘以√3.6
=√(0.4×3.6)
=√1.44
=√1.2²
=1.2
√3分之2乘以√8分之27=
=√(2/3×8/27)
=√(16/81)
=4/9
√2除以3√40
=(1/3)√(2÷40)
=(1/3)√(1/20)
=(1/3)√(5/100)
=(1/3)(√5)/10
=(√5)/30

1999+1998-1997-1996=4
1995+1994-1993-1992=4
……
3+2-1-0=4
所以原式=4×500=2000