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简便计算:0.72X87.5+8.75X0.28

题目详情
简便计算:0.72X87.5+8.75X0.28
▼优质解答
答案和解析
=0.72*25*3.5+0.28*25*0.35
=4*0.18*25*3.5+0.07*4*25*0.35
=100*0.18*3.5+100*0.07*0.35
=100*0.09*2*3.5+100*0.07*0.07*5
=100*0.09*7+100*7*0.0007*5
=100*7(0.09+0.0035)
=100*7*0.0935=7*9.35=65.45