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(1/5+3/4)÷(3/4-1/5) 4/15÷[1-(1/5+2/3)] 9/10+1.5÷(2-75﹪)简便算法

来源:学生作业帮 编辑:作业帮 分类:数学作业 时间:2024/04/28 14:01:33
(1/5+3/4)÷(3/4-1/5) 4/15÷[1-(1/5+2/3)] 9/10+1.5÷(2-75﹪)简便算法
(1/5+3/4)÷(3/4-1/5)
= (1 + 15/4)÷(15/4-1)
= (4 + 15)÷(15 - 4)
= 19 ÷ 11
= 19/11
4/15÷[1-(1/5+2/3)]
= 4/5 ÷[3 - (3/5 + 2)]
= 4 ÷ [15 - (3 + 10)]
= 4 ÷ 2
= 2
9/10+1.5÷(2-75﹪)
= 0.9 + 1.5 ÷ (2 - 0.75)
= 0.9 + 1.5 ÷ 1.25
= 0.9 + (1.5×4) ÷ (1.25×4)
= 0.9 + 6 ÷ 5
= 0.9 + 1.2
= 2.1