How to Calculate the Logic Circuit Outputs?

Once the Boolean expression for a circuit output has been acquired, the output logic level can be determined for any set of input levels.

These are two illustrations of the evaluating logic circuit output

Let A=0, B=1, C=1, D=1

X = A'BC (A+D)'

 = 0'*1*1* (0+1)'

 = 1 *1*1* (1)'

 = 1 *1*1* 0

 = 0

Let A=0, B=0, C=1, D=1, E=1

X = [D+ ((A+B) C)'] * E

 = [1 + ((0+0)1)'] * 1

 = [1 + (0*1)'] * 1

 = [1+ 0'] *1

 = [1+ 1] * 1

 = 1