tentukan nilai K agar persamaan (K+1)x2-2(k+3)x+3k=0

Jawab
(k+1) x² - 2(k+3) x + 3k = 0
a=k+1, b = -2k-6 , c = 3k
D= 0 , k+1 ≠ 0
b² - 4ac = 0 , k ≠ -1
(-2k - 6)² - 4(k+1)(3k) = 0
4k² + 24 k + 36 - 12k² - 12k = 0
-8k² + 12 k + 36 = 0 || bagi -4
 2k² - 3 k  - 9 = 0
(2k - 3)(k + 3) = 0
2k - 3 = 0  atau k+ 3 = 0
k= 3/2   atau k = - 3