5⼀9x2⼀21 5⼀9x10⼀21 4⼀9x4⼀7用简便方法计算?

2024-12-26 01:27:15
推荐回答(2个)
回答1:

依据题意列式计算如下:
5/9×2/21+5/9×10/21+4/9×4/7
=5/9×(2/21+10/21)+4/9×4/7
=5/9×4/7+4/9×4/7
=4/7×(5/9+4/9)
=4/7
=7分之4

回答2:

5/9×2/21+5/9×10/21+4/9×4/7
=5/9×(2/21+10/21)+4/9×4/7
=5/9×4/7+4/9×4/7
=(5/9+4/9)×4/7
=1×4/7
=4/7