Answer:
The coordinates of the library are (19,20)
Explanation:
we know that
If the cafeteria is collinear and equidistant from the science building and the library
then
the cafeteria is the midpoint between the science building and the library
The formula to calculate the midpoint between two points is

Let
M ---> the cafeteria
(x1,y1) ----> science building
(x2,y2) ----> library
substitute the given values

so


therefore
The coordinates of the library are (19,20)