# Fundamental Hardware Elements of Computers: Boolean gate combinations

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Now you have learnt logic gates we will take a look at how they are combined inside hardware. You may well be asked in an exam to draw your own logic gates or to work out what a combination of logic gates will output. In this section we will look at the best way to describe what a set of logic gates is in boolean algebra. Let's take a look at a quick example:

 Exercise: Logic gate combination outputs For the following logic gate combinations work out output Q for each: Answer: Answer: Answer: This equation can be simplified to equal ${\displaystyle A.B}$, as ${\displaystyle B.B=B}$, we'll find out why this is the case in the simplifying boolean equations section coming up Answer: This equation can be simplified to equal 0 (always false), as ${\displaystyle {\overline {A+B}}.A=0}$, we'll find out why this is the case in the simplifying boolean equations section coming up Answer: