Answer: 5k^2-7k-4
Step-by-step explanation: substitute (k-1) in for the x's
5(k-1)^2+3(k-1)-6
(k-1) * (k-1) = k^2-2k-1
5(k^2-2k-1) = 5k^2-10k+ 5
then do 3(k-1)-6
3k-3-6 (combine like terms)
3k-9
5k^2-10k+5 +3k-9 (combine like terms again)
5k^2-7k-4
hope this helps (^_^)