下面各题怎样简便怎样算(求未知数x).69.58-17.5+13.42-2.51318×(913×19-913)x:5=4:(1-38)12.5×3.2×2.53.146×55-3.146×45110+140+188+1154.-数学
题文
下面各题怎样简便怎样算(求未知数x).
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题文
下面各题怎样简便怎样算(求未知数x).
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题型:解答题 难度:中档
答案
(1)69.58-17.5+13.42-2.5, =(69.58+13.42)-(17.5+2.5), =83-20, =63; (2)
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=9; (3)x:5=4:(1-
(1-
x=32; (4)12.5×3.2×2.5, =12.5×(4×0.8)×2.5, =(12.5×0.8)×(4×2.5), =10×10, =100; (5)3.146×55-3.146×45, =3.146×(55-45), =3.146×10, =31.46; (6)
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