习题1.5第1题答案
(1)-10
(2)0
(3)-1/250000
(4)-64/9
习题1.5第2题答案
(1)(-3)×(-4)×(-5)
=-3×4×5
=-60
(2)(-7/8)×15×(-8/7)
=7/8×15×8/7
=(7/8×8/7)×15
=1×15
=15
习题1.5第3题答案
(1)(-1)×(2-5)
=(-1)×2+(-1)×(-5)
=-2+5
=3
(2)8-3×(4-6)=8-3×(-2)
=8+3×2
=14
(3)(-3/4)×(-8+2/3-4/3)
=-[3/4×(-8)+3/4×2/3-3/4×4/3]
=-(-7+1/2)
=-(-6 1/2)
=61/2
(4)(-1.2)×(-5/8)+(-24)×1/12
=1.2×5/8+(-2)
=6/5×5/8-2
=3/4-2
=-1又1/4
习题1.5第4题答案
(1)原式=4/3×4/3=16/9
(2)原式=3/5×5/3=1
(3)原式=-1.84×2=-3.68
(4)原式=1/4×1/4=1/16
(5)原式=0
(6)原式=-3/4×8/45=-2/15
习题1.5第5题答案
(1)-6÷(-0.25)×5/6
=6÷0.25×5/6
=6×4×5/6
=20
(2)(-17)×(-9)×0×37=0
(3)(-60)×(3/4)+5/6-11/15-7/12)
=-(60×3/4+60×5/6-60×11/15-60×7/12)
= -(45+50-44-35)
=-16
(4)-9×(-11)-12×(-8)=99-(-96)
=99+96
=195
习题1.5第6题答案
(1)原式=1-1/5×(-3-4×18/5+4×53/10)
=1-1/5×(-3-72/5+106/5)
=1-1/5×(-15/5-72/5+106/5)
=1-1/5×19/5
=6/25
(2)原式(1/20-15/20)×(10/14-5/14)
=-14/20×5/14
=-1/4
(3)原式=-22/7×(22/7-4/3)×7/22÷(-22/21)
=22/7×38/21×7/22×21/22
=19/(11)
(4)原式=[4-(12+12-40)]÷5=20÷5=4
习题1.5第7题答案
(1)6
(2)-6
(3)-1/5
(4)-5