13n^2 -3n should be the answer
<span>6 yr 7 months+ 2 yr 11 months = ?
6 yr + 2 yr = 8 yr
7 months + 11 months = 18 months = 1 yr 6 months
8 yr + </span>1 yr 6 months = 9 yr 6 months
answer is C<span>. 9 yr 6 months</span>
Answer:

Step-by-step explanation:
An irrational number is a number that isn't a whole number (integer).
= 7.07
= 1
= 5
= 3
The first one is the only one that isn't an integer. So it is the answer.