`1/3xx1/4+1/3xx6/5 -1/3`

`=1/3xx1/4+1/3xx6/5-1/3.1=1/3xx(1/4+6/5-1)`

`=1/3xx9/20`

`=3/20`

`@Nae`

Tham khảo

Cạnh hình vuông là :

24 : 4 = 6 ( m )

Diện tích hình vuông là :

6 × 6 = 36( m² )

Chiều cao hình tam giác là :

(36 × 2) : 12 = 6( m )

`@Nae`

`a)`

`(105/31-31/202+104/91)xx(1/2-1/3-1/6)`

`=(105/31-31/202+104/91)xx(3/6-2/6-1/6)`

`=(105/31-31/202+104/91)xx0/6`

`=(105/31-31/202+104/91)xx0`

`=0`

`b)`

`6/7:(2/5xx6/7)`

`=6/7:2/5xx6/7`

`=(6/7:6/7):2/5`

`=1:2/5`

`=5/2`

`c)`

`6/7 + 5/7 : 5 - 8/9`

`=6/7+1/7-8/9`

`=9/9-8/9`

`=1/9`

`d)`

`6/7 + 5/8 . 1/5 - 3/16 .4`

`=6/7+1/8-3/4`

`=(48+7-12)/56`

`=13/56`

`@Nae`

 `-3/5xx9/14-3/5xx5/14+3/5`

`=(-3/5+3/5)xx(9/14+5/14)xx3/5`

`=0xx14xx3/5`

`=0xx1xx3/5`

`=0xx3/5`

`=0`

`@Nae`

`a,125xx(-4)xx(-16)xx25xx8`

`=(125.8)xx{ (-4).25}xx(-16)`

`=1000xx(-100)xx(-16)`

`=1600000`

`b,16.(38+2)-38xx( 16 - 2)`

`= 16xx38+16xx2-38xx16+38xx2`

`=2xx(16 + 38)`

`=2xx54`

`=108`

`@Nae`