有两堆煤，原来第一堆和第二堆的比是15：7，从第一堆运走后，这时第二堆还比第一堆少3.5吨，第一堆原有煤多少吨？
直接写得数．= 24÷= = == ﹣= = ﹣×=
直接写出得数：3﹣1.2= （0.1）3= 3÷1= ×0.4=﹣= ×7= +1= 5×÷5×=+×= 21÷3=
直接写得数．×4= 6﹣= ÷= ×=×= ÷= ÷= ÷=
= 2.5= = 1== 1×= 3÷1%= =．
×0= ×= ÷= ÷=
后，这时第二堆还比第一堆少3.5吨，第一堆原有煤多少吨？
= 24÷
= 
= 
=
= 
﹣
= 
= 
=
﹣1.2= （0.1）3= 3÷1
= 
×0.4=
﹣
= 
×7= 
+1
= 5×
÷5×
+
×
= 21
÷3=
×4= 6﹣
= 
÷
= 
×
×
= 
÷
= 
÷
= 
÷
=
= 2.5
= 
= 1
=
= 1
×
= 3÷1%= 
=．
×0= 
= 
= 
=
粤公网安备 44130202000953号