Yes the discriminant was really ridiculous, in the end i think i got
-96k^2 +56k + 96 =0
changed the signs, divided by 8 then got it
then the also ridiculous factorising which took me 5+ minutes to figure out it went from
12k^2 - 7k -12=0 to
(4k+3)(3k-4)=0
getting k as -3/4 and 4/3