作业帮26乘 百分之60加5分之3乘44加30 乘零点6
来源：学生作业帮助网 编辑：作业帮 时间：2024/04/28 00:16:41
7分之3乘4分之1加百分之25乘7分之2加0.25乘7分之1=0.25×（7分之3+7分之2+7分之1）=4分之1×7分之6=14分之3
1/(1*2*3)+1/(2*3*4)an=1/[n(n+1)(n+2)]=[(n+2)-(n+1)]/[n(n+1)(n+2)]=1/n(n+1)-1/n(n+2)=[1/n-1/(n+1)]-(1
1乘3乘5分之4加3乘5乘7分之4+...+95乘97乘99分之4=1/(1×3)-1/(3×5)+1/(3×5)-1/(5×7)+...+1/(95×97)-1/(97×99)=1/(1×3)-1/
=[1/(1*3)-1/(3*5)]+[1/(3*5)-1/(5*7)]+.+[1/(95*97)-1/(97*99)]=1/(1*3)-[1/(3*5)-1/(3*5)]-.-[1/(95*97)-
(1*2*3+2*4*6+3*6*9+4*8*12)/(3*4*5+6*8*10+9*12*15+12*16*20)=(1*2*3)(1+8+27+64)/(3*4*5)(1+8+27+64)=(1*
3乘4乘5分之一加4乘5乘6分之1加5乘6乘7分之1加6乘7乘8分之1.98乘99乘100分之1=1/2[1/3*4-1/4*5]+1/2[1/4*5-1/5*6]+...+1/2[1/98*99-1
1乘2分之1加2乘3分之1加3乘4分之1加4乘5分之1加5乘6分之1加6乘7分之1=1-1/2+1/2-1/3+1/3-1/4+1/4-1/5+1/5-1/6+1/6-1/7=1-1/7=6/7=7分
原式=1/2*(1/2*3-1/3*4+1/3*4-1/4*5+.+1/8*9-1/9*10)=1/2*(1/6-1/90)=1/2*(14/90)=7/90
=8.6×2.7+62×0.14+3.5×8.6=8.6×(2.7+3.5)+6.2×1.4=8.6×6.2+6.2×1.4=(8.6+1.4)×6.2=10×6.2=62
1/2*3+1/3*4+1/4*5+……+1/49*50=(1/2-1/3)+(1/3-1/4)+(1/4-1/5)+……+(1/49-1/50)=1/2-1/3+1/3-1/4+1/4-1/5+……
解10.5-(3/4+0.375)÷3/5×10%——是这样吗?=10.5-(3/4+3/8)÷3/5×10%=10.5-9/8×5/3×0.1=10.5-15/8×1/10=10.5-3/16=10
原式=5分之12+35分之17（0.6+0.4）=5分之12+35分之17=35分之101
4949/19800因为1/n(n+1)(n+2)=1/n(1/(n+1)-1/(n+2))=1/n-1/(n+1)-1/2(1/n-1(n+1))
57乘百分之75加44乘0.75减4分之3=57*0.75+44*0.75-0.75=（57+44-1）*0.75=100*0.75=75
2/(1×2×3)+2/(2×3×4)+...+2/(28×29×30)=2*1/2*[1/(1×2)-1/(2×3)+1/(2×3)-1/(3×4)+...+1/(28×29)-1/(29×30)]
=1*2*3(1+2*2*2+7*7*7)/[1*3*5(1+2*2*2+7*7*7)]=1*2*3/(1*3*5)=2/5
75×60%+24×¾+0.6=¾×60+24×¾+0.6=¾×84+0.6=63.6
3-1/2X+2/75=1/6X+1/62/3X=3/121X=2/121