Question

12、908×501-[731×1389-（547×236+842×731-495×361）]=

5448

Answer 1

分析：去括號，分步使用分配律進行計算．

解答：解：原式=908×501-731×1389+（547×236+842×731-495×361）
=908×501-731×1389+547×236+842×731-495×361
=908×501-731×（1389-842）+547×236-495×361
=908×501-731×547+547×236-495×361
=908×501-（731-236）×547-495×361
=908×501-495×547-495×361
=908×501-495×（547+361）
=908×501-495×908
=908×（501-495）
=908×6
=5448．
故本題答案為：5448．

點評：本題考查的是有理數的運算．注意先去括號，觀察算式的特點，靈活使用運算律．