`=>`
Bài 1:
$a)$ `70kg` `3g=70,003kg`
`5m` `7cm=5,07m`
`5` `tấn` `7` `tạ=5,7` `tấn`
`8,556kg=855,6` `tạ`
`0,5` `tấn=500kg`
`4/5` `tạ=0,08` `tấn`
$b)$ `7200m=7,2km`
`5km` `7m=5,007km`
`5,65m=0,0565hm`
`8,5dm=0,85m`
`0,5cm=0,005m`
`4/5 km=800m`
$c)$ `7000 dm^2=70 m^2`
`5 m^2 7 dm^2=5,07 m^2`
`5 m^2 7 cm^2=5,0007 m^2`
`8,5 cm^2=0,00085 m^2`
`0,5 m^2=50 dm^2`
`4/5 m^2=80 dm^2`
Bài 2:
$a)$ `3 m^2 12 dm^2=2,12 \underline{m^{2}}`
`4 m^2 5 dm^2=4,05 \underline{m^{2}}` (Chỗ này đề thiếu 1 số `0` ạ.)
`7 m^2 2036 \underline{cm^{2}}=7,2036 m^2`
`5 \underline{m^2} 134 cm^2=5,0134 m^2`
$b)$ `23 \underline{dm^2} =0,23 m^2`
`40 dm^2=0,40 \underline{m^2}`
`2435 \underline{dm^2}=24,35 m^2`
`407 cm^2=0,0407 \underline{m^2}`
$c)$ `5728 m^2=0,5728 \underline{ha}`
`2070 \underline{m^2}=0,2070 ha`
`412 m^2=0,0412 \underline{ha}`
`2 m^2 76 \underline{cm^2}=2,0076 m^2`
Bài 4:
$a)$ `x+4,32=8,67`
`x=8,67-4,32`
`x=4,35`
$b)$ `x-3,64=5,86`
`x=5,86+3,64`
`x=9,5`
$c)$ `x\times 0,34=1,19\times 1,02`
`x\times 0,34=1,2138`
`x=1,2138: 0,34`
`x=3,57`
$d)$ `x-2,751=6,3\times 2,4`
`x-2,751=15,12`
`x=15,12+2,751`
`x=17,871`
$e)$ `x-1,27=13,5: 4,5`
`x-1,27=3`
`x=3+1,27`
`x=4,27`
$g)$ `x+18,7=50,5: 2,5`
`x+18,7=20,2`
`x=20,2-18,7`
`x=1,5`
$h)$ `53,2: (x-3,5)+45,8=99`
`53,2: (x-3,5)=99-45,8`
`53,2: (x-3,5)=53,2`
`x-3,5=53,2: 53,2`
`x-3,5=1`
`x=1+3,5`
`x=4,5`
$d)$ `4,25\times (x+41,5)-125=53,5`
`4,25\times (x+41,5)=53,5+ 125`
`4,25\times (x+41,5)=178,5`
`x+41,5=178,5: 4,25`
`x+41,5=42`
`x=42-41,5`
`x=0,5`
