Nilai m yang membuat persamaan X2 - 4X+ m= 0 mempunyai akar kembar adalah.......

x1 = 6 ==> ax2 – 5x + 18 = 0
a.62 – 5.6 + 18 = 0
36a – 30 + 18 = 0
36a = 12
a = 1/3
(1/3)x2 – 5x + 18 = 0
x2 – 15x + 54 = 0
(x – 6)(x – 9) = 0
x2 = 9

Semoga bermanfaat