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1.2*3.1+2.5 等于 6.22 这个最简便。。。望采纳谢谢 ···
=1.2×3+1.2×0.1+2.5=3.6+0.12+2.5=3.72+2.5=6.22
1.2*3.1+2.5=（1.2*3）+（1.2*0.1）+2.5=3.6+0.12+2.5=6.22
1.2*3.1+2.5=1.2*（3+0.1）+2.5=3.6+0.12+2.5=6.1+0.12=6.22希望对您有所帮助
