` a) ` ` 10 - [(8^2 - 48).5 + (2^3 - 10 + 8)] : 28 `
` = 10 - [(64 - 48).5 + (8 - 10 + 8)] : 28 `
` = 10 - [16.5 + 6] : 28 `
` = 10 - (80 + 6) : 28 `
` = 10 - 86:28 `
` = 10 - 43/14 `
` = 97/14 `
` b) ` ` 10 - [(8^2 - 48).5 + (2^3 . 10 + 8)] : 28 `
` = 10 - [(64 - 48).5 + (8.10 + 8)] : 28 `
` = 10 - [16.5 + 80 + 8] : 28 `
` = 10 - [86 + 88] : 28 `
` = 10 - 87/14 `
` = 53/14 `