tính : a,2/5 x 3/2 – 3/8 : 5/6 + 17/20 b, 2/5 x ( 3/2 – 3/8 : 5/6 ) + 17/20 trình bày rõ ràng

`2/5 × 3/2 – 3/8 : 5/6 +17/20`

`= 3/5 – 3/8 . 6/5 + 17/20`

`=3/5 – 9/20 + 17/20`

`= 12/20 – 9/20 + 17/20`

`=(12-9+17)/20`

`=20/20=1`

`b, 2/5 × (3/2 – 3/8 : 5/6) +17/20`

`=2/5 × (3/2 – 3/8 . 6/5) + 17/20`

`=2/5 × (3/2 – 9/20) + 17/20`

`=2/5 × (30/20 – 9/20) + 17/20`

`=2/5 × 21/20 + 17/20`

`=21/50 + 17/20`

`=42/100 + 85/100`

`=127/100`

~ Học tốt ~