\(2^3.15-\left[115-\left(12-5\right)^2\right]=8.15-\left[115-7^2\right]=120-\left[115-49\right]=120-66=54\)
\(100:\left\{250:\left[450-\left(4.5^3-2^2.25\right)\right]\right\}=100:\left\{250:\left[450-\left(4.125-4.25\right)\right]\right\}=100:\left\{250:\left[450-\left(500-100\right)\right]\right\}\)
\(=100:\left[250:\left(450-400\right)\right]=100:\left(250:50\right)=100:5=20\)
a,23 . 15 -[115-\((\)12-5)2]
= 8. 15 - [115- 72 ]
=120-[115-49]
=120-66
=54
b, 100:{250:[450-\((\)4.53 - 23.25)]}
=100:{250:[450-\((\)4.125-8.25)]}
=100:{250:[450-\((\)500-300)]}
=100:{250:[450-200]}
=100:{250:250}
=100:1
=100