Question

Urgent! DAU COROANA!​

Answer 1

Răspuns:

3$x^{2}$-8x+5=0

3$x^{2}$-3x-5x+5=0

3x(x-1)-5(x-1)=0

(x-1)(3x-5)=0

x-1=0, 3x-5=0

x=1, x=$\frac{5}{3}$

2.  A. $x^{2}$-2x+1=0

$(x-1)^{2}$=0

x-1=0

x=1, A fals

B. $x^{2}$+4x+3=0

$x^{2}$+3x+x+3=0

x(x+3)+x+3=0

(x+3)(x+1)=0

x+3=0⇒x1=-3

x+1=0⇒x2=-1

C. $4x^{2}$-4x+1=0

$(2x-1)^{2}$=0

2x-1=0

2x=1

x=$\frac{1}{2}$

D. $2x^{2}$-7x+5=0

$2x^{2}$-2x-5x+5=0

2x(x-1)-5(x-1)=0

(x-1)(2x-5)=0

x-1=0⇒x1=1

2x-5=0⇒x2=$\frac{5}{2}$