3.09×0.8+0.2用简便方法?
2个回答
展开全部
解:3.09×0.8+0.2等于( 334/125 ),【即等于2.672】
∵已知需求出3.09×0.8+0.2等于多少
A × B + A = A × (B + 1)
∴3.09 × 0.8 + 0.2
= 3.09 × 0.2 × 4 + 0.2
= 0.2 × (3.09 × 4 + 1)
= 2/10 × [(3×100+9)/100 × 4 + 1]
= 1/5 × (309/100 × 4 + 25/25)
= 1/5 × (309/25 + 25/25)
= 1/5 × 334/25
= 334/125
= 2.672
答:3.09×0.8+0.2等于334/125,【即等于2.672】
∵已知需求出3.09×0.8+0.2等于多少
A × B + A = A × (B + 1)
∴3.09 × 0.8 + 0.2
= 3.09 × 0.2 × 4 + 0.2
= 0.2 × (3.09 × 4 + 1)
= 2/10 × [(3×100+9)/100 × 4 + 1]
= 1/5 × (309/100 × 4 + 25/25)
= 1/5 × (309/25 + 25/25)
= 1/5 × 334/25
= 334/125
= 2.672
答:3.09×0.8+0.2等于334/125,【即等于2.672】
推荐律师服务:
若未解决您的问题,请您详细描述您的问题,通过百度律临进行免费专业咨询