(3⼀4+2⼀5)*(2⼀3-2⼀9) (1⼀3+1⼀5)⼀(2⼀3+2⼀5) 用合适的方法计算

2025-06-22 14:16:42
推荐回答(3个)
回答1:

(3/4+2/5)*(2/3-2/9)
=(3/4+2/5)*(6/9-2/9)
= (3/4+2/5)*(4/9)
=(3/4)(4/9)+(2/5)(4/9)
=1/3+8/45
=15/45+8/45
=23/45
(1/3+1/5)/(2/3+2/5)
=(1/3+1/5)/[2(1/3+1/5)]
=1/2

回答2:

(3/4+2/5)*(2/3-2/9)
=23/20×4/9
=23/45

(1/3+1/5)/(2/3+2/5)
=8/15÷16/15
=1/2

回答3:

就通分算喽