Given that the quadrilateral ABCD is a rectangle, ab = 2, ad = 3, e is the moving point on the line BC, f is the midpoint of CD, and ∠ AEF is an obtuse angle, then the range of de length of the line segment is

Given that the quadrilateral ABCD is a rectangle, ab = 2, ad = 3, e is the moving point on the line BC, f is the midpoint of CD, and ∠ AEF is an obtuse angle, then the range of de length of the line segment is

Let CE = x, then be = bc-ce = 3-x
AE^2=BE^2+AB^2=(3-X)^2+4=X^2-6X+13
EF^2=EC^2+FC^2=X^2+1
AF^2=AD^2+DF^2=9+1=10
Because the angle AEF is an obtuse angle, AF ^ 2 > AE ^ 2 + EF ^ 2
That is 10 > x ^ 2-6x + 13 + x ^ 2 + 1
2x^2-6x+4

Fill in the brackets with the appropriate prime number 10 = () + () = () multiplied by () = () - ()
30=( )+( )=( )+( )=( )+( ) 26=( )+（ ）=（ ）+（ ）
Now there are two more questions. Who can,

10=3+7=2×5=13-3
30=13+17=2+11+17
26=7+19=3+23

How to fill in the proper prime number 10 = () + () = () + () in the brackets below

10=3+7=5+5