State Demorgan's theorem's and prove both theorems using truth table.
De Morgan’s 1st theorem states that when the OR sum of two variables is inverted, this is the same as inverting each variable individually and then ANDing these inverted variables.
De Morgan’s 2nd theorem says that when the AND product of two variables is inverted, this is the same as inverting each variable individually and then ORing them.
In Boolean equation form it can be written as