Question

Secunoaste ca solutiile x1si x2 ale ecuatiei x2-3x+q=0,q R,verifica conditia 2x1-x2=12.Determinati valoarea lui q..?

Answer 1

Ai S=x1+x2=3
P=x1*x2=q
(Formulele lui Viete)
scoti x2=3-x1 si inlocuiesti in 2x1-x2=12 => 2x1-3+x1=12   =>3x1=15 =>x1=5
x2=3-5=-2
q=x1*x2=(-2)*5=-10