Đáp án:
`2 × 18 × 63 + 4 × 41 × 9 - 3 × 4 × 12`
`= (2 × 18) × 63 + (4 × 9) × 41 - (3 × 12) × 4`
`= 36 × 63 + 36 × 41 - 36 × 4`
`= 36 × (63 + 41 - 4)`
`= 36 × 100`
`= 3600`
`(525 + 315) : 15`
`= 840 : 15`
`= 56`
`(1026 - 741) : 53`
`= 285 : 53`
`=``\frac{285}{53}`