下面各题怎样算简便就怎样算（求未知数X）．5.6：2.8=2.4：x59-513-813+5912.5×6.3+1.25×37(47×15+37×15)÷81536×（34-23）×1235÷[（15+13）÷29]．-数学
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=
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=
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（3）12.5×6.3+1.25×37，
=12.5×6.3+12.5×3.7，
=12.5×（6.3+3.7），
=12.5×10，
=125；
（4）（
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=[（
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=[1×
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=
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=
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（5）36×（
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=36×
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=3×
