5 +10+15+20+25写成乘法算式

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5 +10+15+20+25写成乘法算式

=(5+25)x5/2
=30x5/2
=75

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都是神人啊，我都看不懂

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5+2×5+3×5+4×5+5×5=5(1+2+3+4+5)=75

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