4) During computing the value of an arithmetic expression in a typical modern computer:

a)binary system will be used

b)logic gates will be used

c)changes of voltage levels will happen inside the computer

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5) The NOT operator:

a)corresponds to a logic gate commonly used in modern computers

b)is unary

c)is necessary to represent some Boolean functions

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6) In an 8-bit computer, the representation of -83 in the sign-magnitude encoding is:

a)11010011

b)10101101

c)10101100