几道简便计算的题目 得到正解悬赏会加到100(-5)*8*(-7)*(-0.125)(1/4+1/6-1/2)*12(-56)*(4/7-3/8+1/14)
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几道简便计算的题目 得到正解悬赏会加到100(-5)*8*(-7)*(-0.125)(1/4+1/6-1/2)*12(-56)*(4/7-3/8+1/14)
几道简便计算的题目 得到正解悬赏会加到100
(-5)*8*(-7)*(-0.125)
(1/4+1/6-1/2)*12
(-56)*(4/7-3/8+1/14)
几道简便计算的题目 得到正解悬赏会加到100(-5)*8*(-7)*(-0.125)(1/4+1/6-1/2)*12(-56)*(4/7-3/8+1/14)
(-5)*8*(-7)*(-0.125)
=[(-5)*(-7)]*[8*(-0.125)]
=35*1
=35
(1/4+1/6-1/2)*12
=1/4*12+1/6*12-1/2*12
=3+2-6
=-1
(-56)*(4/7-3/8+1/14)
=(-56)*4/7-(-56)*3/8+(-56)*1/14
=-32+21-4
=-15
*是乘的意思? 第一个-35 第二个-1 第三个-15
(-5)*8*(-7)*(-0.125)=(-5)*8*(-7)*(1/8)=(-5)*(-7)=-35(记住0.125=1/8)
(1/4+1/6-1/2)*12=1/4*12+1/6*12-1/2*12=3+2-6=-1
(-56)*(4/7-3/8+1/14)=(-56)*4/7-(-56)*3/8+(-56)*(1/14)=-32+21-4=21-36=-15
(-5)×8×(-7))×(-0.125)
=8×(-0.125)×(-5)×(-7))
=-1×35
=-35
(1/4+1/6-1/2)×12
=1/4×12+1/6×12-1/2×12
=3+2-6
=5-6
=-1
(-56)×(4/7-3/8+1/14)
=-56×4/7-﹙-56×3/8﹚+﹙-56×1/14﹚
=-32+21-14
=-11-14
=-15
1、本题采用——乘法交换律
(-5)*8*(-7)*(-0.125)=(-5)*(-7)*(-0.125)*8
=35*(-1)
=-35
2、本题采用乘法对加法的分配律。即:a(b+c)=ab+ac
(1/4+...
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1、本题采用——乘法交换律
(-5)*8*(-7)*(-0.125)=(-5)*(-7)*(-0.125)*8
=35*(-1)
=-35
2、本题采用乘法对加法的分配律。即:a(b+c)=ab+ac
(1/4+1/6-1/2)*12=(1/4)*12+(1/6)*12-(1/2)*12
=3+2-6
=-1
3、本题同——2
(-56)*(4/7-3/8+1/14)=(-56)*(4/7)-(-56)*(3/8)+(-56)*(1/14)
=(-32)+21+(-4)
=-15
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