计算下列各题,能简算的要简算.
〔-(-)〕÷=
÷5+5÷=÷〔÷(-)〕=48×+3÷7=?×÷(-)=62.5%×15+2×-5÷8=
网友回答
解:(1)[-(-)]÷,
=[-+]÷,
=[+-]÷,
=[1-]÷,
=,
=;
(2)÷5+5÷,
=+6,
=6;
(3)÷[÷(-)],
=÷[÷],
=÷,
=;
(4)48×+3÷7,
=48×+,
=(48+1)×,
=49×,
=21;
(5)×÷(-),
=×÷,
=÷,
=;
(6)62.5%×15+2×-5÷8,
=×15+2×-,
=×(15+2-1),
=×16,
=10.
解析分析:(1)先去掉小括号,再把中括号里面的运算运用加法交换律简算,最后算括号外的除法;
(2)同时运算除法,再算加法;
(3)先算小括号里面的减法,再算中括号里面的除法,最后算括号外的除法;
(4)(6)先把除法写成分数,再运用乘法分配律简算;
(5)先算小括号里面的减法,再算括号外的乘法,最后算除法.
点评:本题考查了四则混合运算,注意运算顺序和运算法则,灵活运用所学的运算定律进行简便计算.