用适当的方法做下面各题.(f)2我×(40+6)(2)44×44(大)(我8+76)×f2(4)720-(7我0÷f我+248)-数学

题目简介

用适当的方法做下面各题.(f)2我×(40+6)(2)44×44(大)(我8+76)×f2(4)720-(7我0÷f我+248)-数学

题目详情

用适当的方法做下面各题.
(f)2我×(40+6)
(2)44×44
(大)(我8+76)×f2
(4)720-(7我0÷f我+248)
题型:解答题难度:中档来源:不详

答案

(1)25×(dg+7),
=25×dg+25×7,
=1ggg+15g,
=115g;
(2)d9×99,
=d9×(1gg-1),
=d9×1gg-d9×1,
=d9gg-d9,
=d751;
(3)(57+77)×12,
=13d×12,
=(1gg+3d)×12,
=1gg×12+3d×12,
=12gg+3d×(1g+2),
=12gg+3d×1g+3d×2,
=12gg+3dg+77,
=17g7;
(d)72g-(75g÷15+2d7),
=72g-(5g+2d7),
=72g-297,
=72g-(3gg-2),
=72g-3gg+2,
=d22.

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