Question

Tentukan penyelesaian persamaan kuadrat berikut dengan melengkapkan bentuk kuadrat...
X^2-8x+13=0
x^2-5x=-5

Answer 1

X^2 - 8x + 13 = 0
=> x^2 - 8x + .... = -13 + ....
=> x^2 - 8x + 16 = -13 + 16
=> (x - 4)^2 = 3
=> x - 4 = ±√3
=> x = 4 ± √3
x = 4 + √3 atau x = 4 - √3

x^2 - 5x + .... = -5 + ....
=> x^2 - 5x + (25/4) = -5 + (25/4)
=> (x - 5/2)^2 = 5/4
=> (x - 5/2) = ±√5/2
=> x = 5/2 ± √5/2 = 1/2 (5 ± √5)
x = 1/2 (5 + √5) atau x = 1/2 (5 - √5)