## Prealgebra (7th Edition)

$72-\{18-[40\div(5\times1)+2]+52\}$ $\longrightarrow$ first resolve the innermost group, the parenthesis = $72-\{18-[40\div5+2]+52\}$ $\longrightarrow$ resolve the innermost group, now the brackets, divide then add as specified by the order of operations = $72-\{18-[8+2]+52\}$ $\longrightarrow$ add within the brackets = $72-\{18-10+52\}$ $\longrightarrow$ subtract then add within the braces, working left to right = $72-\{8+52\}$ $\longrightarrow$ add = $72-60$ $\longrightarrow$ subtract =$12$