`9` phút `36` giây `:` `4` `+` `2` giờ `24` phút `:` `4`

`=396` giây `:` `4` `+` `144` phút `:` `4` 

`=99` giây `+` `36` phút 

`=` `36` phút `99` giây 

th lười sửa quá xoá ik =))

khongcochii<33

Tc : `36cm^2=6xx6`

`=>` Cạnh hình vuông là `6cm`

Chu vi là:

`6 xx 4 = 24 (cm) `

à quên rút gọn \(\dfrac{39}{15}=\dfrac{13}{5}\)

`3-(1/6-x).2/3=2/3-2x`

`=>3-1/6+2/3x-2/3+2x=0`

`=>(2/3x+2x)+(3-1/6-2/3)=0`

`=>(2/3x+6/3x)+(18/6-1/6-4/6)=0`

`=>8/3x+(17/6-4/6)=0`

`=>8/3x+13/6=0`

`=>8/3x=0-13/6`

`=>8/3x=-13/6`

`=>x=-13/6:8/3`

`=>x=-13/6 . 3/8`

`=>x=-39/48`

`=>x=-13/16`

Vậy `x=-13/16`

`#Dalziel`

Sắp có cfs nghe =)) 

`1/2xx3/4:6/5`

`=1/2xx3/4xx5/6`

`=3/8xx5/6`

`=15/48`

`=5/16`

__

`2/3+1/6:7/12`

`=2/3+1/6xx12/7`

`=2/3+2/7`

`=14/21+6/21`

`=20/21`

__

`8xx3/5:12/5`

`=8xx3/5xx5/12`

`=8xx1/4`

`=8/4`

`=2`

__

`4/9+3/4-1/3`

`=(4/9-1/3)+3/4`

`=(4/9-3/9)+3/4`

`=1/9+3/4`

`=4/36+27/36`

`=31/36`