Question

Solve for the unknown:8k-k2=42

and tell me how you did it I have no ideal how

Answer 1

k = 4 + 5.10i , 4 - 5.10i

Explanation:

8k - k^2 = 42

k^2 - 8k + 42 = 0

Completing the square:-

(k - 4)^2 - 16 +42 = 0

(k - 4)^2 = -26

k- 4 = +/-sqrt26

k = 4 + sqrt26 or 4 - sqrt26

k = 4 + 5.10i , 4 - 5.10i