Answer:
The multiple zero is
.
The multiplicity is 2
Step-by-step explanation:
The given function is

To find the zero of this function, we equate it to zero.

We factor to obtain;

Observe that; the expression within the parenthesis is a perfect square.
This implies that;

This implies that;
Either
or 
has a multiple zero which is
and its multplicity is 2.
13) B. 8.47,8.67,8.7
14) A
Just ask for explanation if u need it
Hope that helped :)