Respuesta :

5k^2–7k-4 it says I have to write 20 characters so here

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 (^_^)