d) E= 21$\frac{2}{5}$ . $\frac{14}{15}$ + (-16$\frac{2}{5}$ ) . $\frac{14}{15}$ 02/10/2021 Bởi Parker d) E= 21$\frac{2}{5}$ . $\frac{14}{15}$ + (-16$\frac{2}{5}$ ) . $\frac{14}{15}$
`d)` `E=21 2/5 .14/15+(-16 2/5).14/15` `E=14/15 .[21 2/5 +(-16 2/5)]` `E=14/15 .5` `E=14/3` Bình luận
`d)`
`E=21 2/5 .14/15+(-16 2/5).14/15`
`E=14/15 .[21 2/5 +(-16 2/5)]`
`E=14/15 .5`
`E=14/3`
Đáp án:
d,E=14/15.(21+2/5-16-2/5)
=14/15.[(21-16)+(2/5-2/5)]
=14/15.(5+0)=14/15.5=14/3