Ta có :
`400:(5.4-5.2^{3})`
`=400:(5.4-5.8)`
`=400:(20-40)`
`=400:(-20)`
`=-20`
Vậy `400:(5.4-5.2^{3})=-20`
Ta có :
`49-(-54)-23`
`=49+54-23`
`=103-23`
`=80`
Vậy `49-(-54)-23=80`
Ta có :
`80-[130-(12-4)^{2}]`
`=80-(130-8^{2})`
`=80-(130-64)`
`=80-66`
`=14`
Vậy `80-[130-(12-4)^{2}]=14`