计算:
①+-=②3.2-0.85-1=③3.2×-÷2=④1.725×4×0.5=⑤(+)÷=⑥1.8×0.72+1.28×1.8=⑦2÷(-)=⑧57.6÷[(1.25+25%)×0.32]=.
网友回答
解:①+-
=-,
=;
②3.2-0.85-1
=2.35-1.8,
=0.55;
③3.2×-÷2
=2-,
=1;
④1.725×4×0.5
=1.725×(4×0.5),
=1.725×2,
=3.5;
⑤(+)÷
=×+×,
=+1,
=2;
⑥1.8×0.72+1.28×1.8
=1.8×(0.72+1.28),
=1.8×2,
=3.6;
⑦2÷(-)
=2÷,
=12;
⑧57.6÷[(1.25+25%)×0.32]
=57.6÷[1.5×0.32],
=57.6÷0.48,
=120.
解析分析:①②③⑦⑧根据四则混合运算法运算顺序计算即可:先算乘除,再算加减,有括号的要先算括号里面的;④可根据乘法结合律计算;⑤⑥可根据乘法分配律计算;
点评:当算式中同时含有中括号与小括号时,要注意先算小括号里面的,再算中括号里面的.