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67.28+0.75*12.5/0.625-81.75+0.472.25*2.4+77.5*0.24（1.2/0.3-0.3/1.25）/0.25*8（30-9.8）*0.6-2.12/10+90（1.4238-35.82/25）+8.375*2.56/0.2144307.8-136.8+127*（1-0.84/2.1）/0.751990*198.9-1989*198.8
题目详情
67.28+0.75*12.5/0.625-81.75+0.47
2.25*2.4+77.5*0.24
（1.2/0.3-0.3/1.25）/0.25*8
【（30-9.8）*0.6-2.12】/10+90
【（1.4238-35.82/25）+8.375*2.56】/0.2144
307.8-【136.8+127*（1-0.84/2.1）/0.75】
1990*198.9-1989*198.8
▼优质解答
答案和解析
1、67.28+0.75*12.5/0.625-81.75+0.47
=（67.28+0.47）+3/4*25/2*8/5-81.75
=67.75+15-81.75
=82.75-81.75
=1
2、2.25*2.4+77.5*0.24
=22.5*0.24+77.5*0.24
=0.24*(22.5+77.5)
=0.24*100
24
3、(1.2/0.3-0.3/1.25)/0.25*8
=(4-0.24)*4*8
=3.76*4*8
=120.32
4、((30-9.8)*0.6-2.12)/10+90
=(20.2*0.6-2.12)/10+90
=(12.12-2.12)/10+90
=10/10+90
=1+90
=91
5、((1.4238-35.82/25)+8.375*2.56)/0.2144
=((1.4238-1.4328)+21.44)/0.2144
=(-0.009+21.44)/0.2144
=21.431/0.2144
=99.958
6、307.8-(136.8+127*(1-0.84/2.1)/0.75)
=307.8-(136.8+127*(1-0.4)/0.75)
=307.8-(136.8+127*0.6/0.75)
=307.8-(136.8+76.2/0.75)
=307.8-(136.8+101.6)
=307.8-238.4
=69.4
7、1990*198.9-1989*198.8
=1990*198.9-198.9*1988
=198.9*(1990-1988)
=198.9*2
=397.8
=（67.28+0.47）+3/4*25/2*8/5-81.75
=67.75+15-81.75
=82.75-81.75
=1
2、2.25*2.4+77.5*0.24
=22.5*0.24+77.5*0.24
=0.24*(22.5+77.5)
=0.24*100
24
3、(1.2/0.3-0.3/1.25)/0.25*8
=(4-0.24)*4*8
=3.76*4*8
=120.32
4、((30-9.8)*0.6-2.12)/10+90
=(20.2*0.6-2.12)/10+90
=(12.12-2.12)/10+90
=10/10+90
=1+90
=91
5、((1.4238-35.82/25)+8.375*2.56)/0.2144
=((1.4238-1.4328)+21.44)/0.2144
=(-0.009+21.44)/0.2144
=21.431/0.2144
=99.958
6、307.8-(136.8+127*(1-0.84/2.1)/0.75)
=307.8-(136.8+127*(1-0.4)/0.75)
=307.8-(136.8+127*0.6/0.75)
=307.8-(136.8+76.2/0.75)
=307.8-(136.8+101.6)
=307.8-238.4
=69.4
7、1990*198.9-1989*198.8
=1990*198.9-198.9*1988
=198.9*(1990-1988)
=198.9*2
=397.8
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