can someone please help me trying to find the centre of the following subgroup
where a,b,c belong to Reals and ac not equal to zero
then equating to find the values of a b and c. but have had no luck
also tried replacing f,g,h with 1's and 0's with no luck
the answer is Z(H)=
Got an exam in a couple of days so any help appreciated. Can never do these kinds of questions so a general method would be nice.