某列火车通过500米长的隧道用了40秒，通过200米长的桥梁用了25秒，假设这列火车通过隧道和桥梁的平均速度相同，这列火车长多少米？
①=②=③= ④= ⑤= ⑥=⑦=⑧= ⑨= ⑩= ．
直接写出得数．+=﹣= 3×=÷=+=÷= 1﹣=×=
直接写出得数．==== 2÷3====
+=﹣=×= 14÷=÷=×=÷= 6×=
直接写得数： 1﹣= 9×=÷2=÷== 1=×1.3=×=
=②
=③
= ④
= 
= ⑥
=⑦
=⑧
= 
= ⑩
= ．
+
=
﹣
=
÷
=
+
=
÷
= 1﹣
=
×
=
=
=
=
=
=
=
=
+
=
﹣
=
= 14÷
=
÷
=
×
=
÷
= 6×
=
= 9×
=
÷2=
÷
= 1
=
×1.3=
×
=
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