1/5x(3.4+3.4+3.4+3又2/5+17/5)
=1/5×5×3.4
=1×3.4
=3.4
0.32-(0.32-7/10+0.32)
=0.32-0.32+7/10-0.32
=7/10-0.32
=0.38
64又1/20x1/20
=（60+81/20）×1/20
=60×1/20+81/20×1/20
=3+81/400
=3又81/400
0.76x5又3/10+0.76x3又7/10+0.76
=0.76x(5又3/10+3又7/10+1）
=0.76x10
=7.6
2008÷2007/2006
=2008×2006/2007
=（2007+1）×2006/2007
=2007×2006/2007+2006/2007
=2006+2006/2007
=2006又2006/2007