tentukan nilai x dari:(x-1)²=5

(x - 1)^2 = 5
x - 1 = V5
x = 1 +- V5
x1 = 1 + V5
x2 = 1 - V5

(x-1)^2 = 5
X^2 - 2X + 1 = 5
X^2 -2X -4 = 0
A = 1, B = -2, C = -4
-B plusminus√B^2 -4AC : 2A
2 plusminus √4 + 16 : 2
2 plusminus √20 : 2
2 plusminus 2√5 : 2

X1= 2 + 2√5 : 2
= 1 + √5

X2= 2 - 2√5 : 2
= 1 - √5