`2^3:8xx(12^3-3^3xx2^6+1284)`
`=8:8xx[12^3-3^3xx(2^2)^3+1284)`
`=8:8xx[12^3-(3xx2^2)^3+1284]`
`=8:8xx[12^3-(3xx4)^3+1284]`
`=8:8xx(12^3-12^3+1284)`
`=8:8xx(0+1284)`
`=8:8xx1284`
`=1xx1284`
`=1284`
Vậy: `...`
2^3 : 8 x (12^3 - 3^3 x 2^6 + 1284)
= 1 x (1728 - 1728 + 1284)
= 1284