(1):x=2:1.8?????????
(2)[(1.4+1.6×2)×(1÷-2.375)]+2.901
(3)2007×20082008-2008×20072007???????
(4)++++…+.
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解:(1):x=2:1.8,
????????? x=×1.8,
????????? 2.8x=1,
???????????? x=
(2)[(1.4+1.6×2)×(1÷-2.375)]+2.901,
=[1.4+3.6]×0+2.901,
=2.901,
(3)2007×20082008-2008×20072007=2007×2008×10001-2008×2007×10001,=0;
(4)++++…+,
=×[1-]÷,
=1-,
=.
解析分析:(1)根据比例的基本性质(在比例里,两个外项的积等于两个内项的积)解答即可;
(2)根据四则运算的运算顺序:先算乘除,再算加、减;
(3)把20082008拆为2008×10001,20072007拆为2007×10001解答即可;
(4)根据等比数列的求和公式解答即可.
点评:根据题目的特点,选择合适的方法解答即可.