小学数学题！急求！急！！！（有算式）能做几道就几道！！！

①126又1/49÷25
=(125+1又1/49)÷25
=125÷25+50/49÷25
=5+2/49
=5又2/49

②（1+1/2+1/3+1/4）×（1/2+1/3+1/4+1/5）-（1+1/2+1/3+1/4+1/5）×（1/2+1/3+1/4）
=(1+1/2+1/3+1/4)(1/2+1/3+1/4+1/5)-(1/2+1/3+1/4)-(1/2+1/3+1/4)(1/2+1/3+1/4+1/5)
=(1/2+1/3+1/4+1/5)(1+1/2+1/3+1/4-1/2-1/3-1/4)-(1/2+1/3+1/4)
=(1/2+1/3+1/4+1/5)-(1/2+1/3+1/4)
=1/5

③48又7/10×999+48.7÷（2-1/2-1/3-1/6）
=48.7*999+48.7÷[2-(1/2+1/3+1/6)]
=48.7*999+48.7÷1
=48.7*(999+1)
=48700

④（1/5+1/7+1/9+1/11）×（1/7+1/9+1/11+1/13）-（1/5+1/7+1/9+1/11+1/13）×（1/7+1/9+1/11 )
同第2题

我只能说一句：出题人太狂了！
这种题应该是能简算的

~~~~~~~~~~~~~~~飘走~~~~~~~~~~~~~~~~

(126+1/49)/25=(125+50/49)/25=25+2/49