递等式计算 578-405÷45×16(46+165÷55)×83[96-(42+36)]×1915×[(45-15)÷3][(325+175)÷5]÷2533×20+560÷70.
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解:(1)578-405÷45×16,
=578-9×16,
=578-144,
=434;
(2)(46+165÷55)×83,
=(46+3)×83,
=49×83,
=4067;
(3)[96-(42+36)]×19,
=[96-78]×19,
=18×19,
=342;
(4)15×[(45-15)÷3],
=15×[30÷3],
=15×10,
=150;
(5)[(325+175)÷5]÷25,
=[500÷5]÷25,
=100÷25,
=4;
(6)33×20+560÷70,
=660+8,
=668.
解析分析:(1)先算除法,再算乘法,最后算减法;(2)先算小括号里面是除法,再算小括号里面的加法,最后算乘法;(3)先算小括号里面的加法,再算中括号里面的减法,最后算乘法;(4)先算小括号里面的减法,再算中括号里面的除法,最后算乘法;(5)先算小括号里面的加法,再算中括号里面的除法,最后算中括号外面的除法;(6)先算乘法和除法,再算加法.
点评:四则混合运算,先弄清运算顺序,然后再进一步计算即可.