Chapter 11.4, Problem 3CVC

Fill in each blank so that the resulting statement is true.

Consider the statement

$3+7+11+\cdots +(4n-1)=n(2n+1)$

If $n=1$, the statement is $3=1(2+1)$.

If $n=2$, the statement is $3+7=2(4+1)$.

If $n=3$, the statement is ________________.

If $n=k+1$, the statement before the algebra is simplified is _______________________________.

If $n=k+1$, the statement after the algebra is simplified is __________________________________.