Assuming the cylinder is closed at both ends
Surface area = 2 pi r^2 + 2 pi r h = 108
now h = r/2 so we have:-
2pi r^2 + pi r^2= 108
3 pi r^2 = 108
r^2 = 11.459
r = 3.385
so the height h = 1.693 m to nearest thousandth
45 plus 67 gives you a number
We are given :

Step 1: factor the part inside square root
The function given inside square root is of quadratic form.
So let us try to factorise it using AC method.
Here A*C = 4*25 = 100
so we have to find factors of 100 that add up to give -20.
the two factors are -10 and -10.
Rewriting the function :

=
=
=
Step 2:
Now we take square root of the factorised form

= 
Answer : (2x-5)