12. Describe the circuit following circuit using an equation. Simplify the equation using switching algebra. Draw the simplified circuit. 13. Draw a truth table far a system with 3 inputs, a, b, c, and d and one output, f. f is 1 iff n is a prime f is iff n is not a prime Natr that, D and 1 are not primes. Primr numbers are 2,3, 5, and7 14. Reduce the expression belaw (using switching algebra) to a sum of products expression with 2 terms and 4 literals, Show each step, a'b'c'a'bcabc ab'c Draw a block diagran far the reduced expression. 15. Consider the following truth table a) Write a canonical SOP sum of minterms function) in numeric form b) Write a sum of minterms function in algebraic farm b) Find a minimum sum of products expression