Question

Tentukan akar - akar persamaan kuadrat berikut dengan cara melengkapkan kuadrat sempurna

- 2Xkuadrat - 15X - 50 = 0 ?

Answer 1

 2X² - 15X - 50 = 0
(2x+5)(x-10)
2x+5=0         x-10=0
x=-5/2            x=10

Answer 2

Cara Kuadrat sempurna :
2x² - 15x - 50 = 0
x² - 15/2x - 25 = 0
x² - 15/2x = 25
x² - 15/2x + 225/16 = 25 + 225/16
x² - 15/2x + 225/16 = 625 /16
(x - 15/4)² = 625/16
( x - 15/4) = √(625/16)
x - 15/4 = + 25/4
x = + 25/4 + 15/4

x1 = 25/4 + 15/4 = 40/4 = 10
x2= -25/4 +15/4 = -10/4 = - 5/2