Chapter 4 - 4.3 - Boolean Logic and Gates - Practice Problems - Page 187: 3

$(x=5)$ $AND$ $(y=11)$ $OR$ $([x+y]=z)$ $True$ $AND$ $False$ $OR$ $True$ We now must make an assumption about which of the two logical operations to do first, the $AND$ $OR$ the $OR$. If we assume the $AND$ goes first, then we get $False$ $OR$ $True$ $True$ If we assume that the $OR$ goes first, then the expression would be evaluated as follows: $True$ $AND$ $True$ $True$ In this case, the answer is the same, but we arrive at the answer in different ways.

$(x=5)$ $AND$ $(y=11)$ $OR$ $([x+y]=z)$ $True$ $AND$ $False$ $OR$ $True$ We now must make an assumption about which of the two logical operations to do first, the $AND$ $OR$ the $OR$. If we assume the $AND$ goes first, then we get $False$ $OR$ $True$ $True$ If we assume that the $OR$ goes first, then the expression would be evaluated as follows: $True$ $AND$ $True$ $True$ In this case, the answer is the same, but we arrive at the answer in different ways.