Answer: C) Contrapositive
The original conditional is in the form "If P, then Q"
The contrapositive is in the form "If not Q, then not P"
You flip the order of P and Q, and you also negate each piece. The original conditional and contrapositive can be proven to have the same truth values through the use of a truth table.
The answer to one would be 25534
11,15,19,23
an = 11 + 4(n-1)
an = 11 + 4n - 4
an = 4n + 7
