Question

Pers. kuadrat x^{2} - 3x + 1 = 0 pers. kuadrat yang akar-akarnya 2x_{1} dan 2x_{2} adalah..

Answer 1

X²-3x+1=0
x1+x2 = -b/a
         = 3

x1.x2 = c/a
         = 1

rumus pers kuadrat : x²-(α+β) x + αβ = 0

jika α = 2x1
     β = 2x2

maka :
x²-(2x1+2x2) x + 2x1.2x2 = 0
x²-2 (x1+x2) x + 4.x1.x2 = 0
x²-2(3)x + 4.1 =0
x²-6x+4=0