Question

Determinati elementele multimii A={x apartine R I x^2-3x+2>=0} si B={x apartine R I Ix+3I<6}. Ajutor va rog.Dau coronita

Answer 1

x^2-3x+2 = 0

delta = 9-8= 1

x1=(3+1)/2 = 4/2 = 2 apartine R

x2 = (3-1)/2= 2/2 = 1 apartine R

A={1,2}

-6<x+3<6 scadem toata inecuatia cu -3

-6-3< x+3-3<6-3

-9<x<3 => x=(-9,3) => B={-8,-7,-6,-5,-4,-3,-2,-1,0,1,2}

Answer 2

Răspuns:

x^2-x-2x+2=x(x-1)-2(x_1)=(x-1)(x-2)=0 ;   x-1=0; x=1 ;   x-2=0 ;  x=2

Explicație pas cu pas:

-6<x+3<6     |  -3 ;  -9<x<3 ; x∈  (-9;3)