Đáp án:

`2^4 *5-[(131-(13-4)^2]`
`=16*5-(131-9^2]`
`=16*5-(131-81]`
`=16*5-50`
`=80-50`
`=30`
``
`100:{250*[450-(4*5^3 -2^2 *25)]}`
`=100:{250*[450-(4*125-4*25)]}`
`=100:{250*[450-(500-100)]}`
`=100:{250*[450-400]}`
`=100:{250*50}`
`=100:12500`
`=1/125`
``
`2^8*15-[115-(12-5)^2]`
`=8*15-[115-7^2)]`
`=8*15-[115-49]`
`=8*15-66`
`=120-66`
`=54`
``
`30*{175:[355-(135+37*5)]}`
`=30*{175:[355-(135+185)]}`
`=30*{175:[355-320]}`
`=30*{175:35}`
`=30*5`
`=150`