tinh bang cach thuan tien : a, 5 3/4: 3+2 1/4x 1/3-3/8

Giải thích các bước giải:

`a)` `5(3)/4:3+2(1)/4×1/3-3/8`

`=23/4×1/3+9/4×1/3-3/8`

`=1/3×(23/4+9/4)-3/8`

`=1/3×32/4-3/8`

`=8/3-3/8`

`=55/24`

`b)` `3/5:5/6:6/7:7/8+2/5+33/35`

`=3/5×6/5×7/6×8/7+2/5+33/35`

`=(3×6×7×8)/(5×5×6×7)+2/5+33/35`

`=24/25+2/5+33/35`

`=24/25+2/5+33/35`

`=168/175+70/175+165/175`

`=403/175`