Tính nhanh có quy luật:
1) 8 x 24 x 6 + 12 x 4 x 52 + 2 x 22 x 24
2) 18 x 58 x 2 – 9 x 27 x 4 – 12 x 69 x 3
3) 30 – 85 x 3 + 18 x 72 x 5 – 45 x 37 x 2 – 9 x 20 x10
Tính nhanh có quy luật:
1) 8 x 24 x 6 + 12 x 4 x 52 + 2 x 22 x 24
2) 18 x 58 x 2 – 9 x 27 x 4 – 12 x 69 x 3
3) 30 – 85 x 3 + 18 x 72 x 5 – 45 x 37 x 2 – 9 x 20 x10
Đáp án:
Giải thích các bước giải:
1 ,`8 . 24 . 6 + 12 . 4 .52 + 2 .22 . 24`
`=48.24+48.52+48.22`
`=48.(24+52+22)`
`=48.98`
`=4704`
2) `18 . 58 . 2 – 9 . 27 . 4 – 12 . 69 . 3`
`=36.58-36.27-36.69`
`=36.(58-27-69)`
`=36.(-38)`
`=-1368`
3) `30 . 85 . 3 + 18 . 72 . 5 – 45 . 37 . 2 – 9 . 20 .10`
`=90.85+90.72-90.37-90.20`
`=90.(85+72-37-20)`
`=90.100=9000`
`1) `
`8 × 24 × 6 + 12 × 4 × 52 + 2 × 22 × 24`
`= 48 × 24 + 48 × 52 + 48 × 22`
`= 48 x (24 + 52 + 22)`
`= 48 × 98 `
`= 4704`
`2)
`18 × 58 × 2 – 9 × 27 × 4 – 12 × 69 × 3 `
`= 36 × 58 – 36 × 27 – 36 × 69`
`= 36 × (58 – 27 – 69)`
`= 36 × (-38)`
`= -1368`
`3)`
`30 × 85 × 3 + 18 × 72 × 5 – 45 × 37 × 2 – 9 × 20 × 10`
`= 90 × 85 + 90 × 72 – 90 × 37 – 90 × 20`
`= 90 × (85 + 72 – 37 – 20)`
`= 90 × 100`
`= 9000`