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①38.4×187-15.4×384+3.3×16.②(5.76×3.84×1.98)÷(2.88×7.68×0.99)③2.01+2.02+2.03+2.04+…+2.49+2.5④1991×199219921992-1992×199119911991.

题目详情
①38.4×187-15.4×384+3.3×16. ②(5.76×3.84×1.98)÷(2.88×7.68×0.99)
③2.01+2.02+2.03+2.04+…+2.49+2.5 ④1991×199219921992-1992×199119911991.
▼优质解答
答案和解析
①38.4×187-15.4×384+3.3×16,
=38.4×187-154×38.4+3.3×16,
=38.4×(187-154)+3.3×16,
=38.4×33+3.3×16,
=3.3×(384+16),
=3.3×400,
=1320;

②(5.76×3.84×1.98)÷(2.88×7.68×0.99),
=(2.88×2×3.84×0.99×2)÷(2.88×3.84×2×0.99),
=2;

③2.01+2.02+2.03+2.04+…+2.49+2.5,
=(2.01+2.50)+(2.02+2.49)+…+(2.25+2.56),
=4.51×25,
=112.75;

④1991×199219921992-1992×199119911991,
=1991×1992×100010001-1992×1991×100010001,
=0.