Question

3.5x0.8+1.2x0.5怎样简便运算

Answer 1

3.5x0.8+1.2x0.5
= 5×0.7×0.8 +0.3×4×0.5
= 5×0.8×0.7+4×0.5×0.3
= 4×0.7+2×0.3
= 2.8+0.6
= 3.4

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Answer 2

3.5x0.8+1.2x0.5
=0.5x5.6+1.2x0.5
=0.5x(5.6+1.2)
=3.4

Answer 3

3.5x0.8+1.2x0.5
=7*0.5x0.4*2+0.4*3x0.5
=0.2*（14+3）
=3.4

Answer 4

先都化成分数：7/2*4/5+6/5*1/2
该约分的约分：14/5+3/5=17/5