Question

cine mă ajută îi voi da coroană ​

Answer 1

Răspuns:

1. a) Δ=b²-4ac= 9-8=1   x1= (-b-$\sqrt{D}$)/2a= (9-1)/2=8/2=4  x1=4

x2= (-b+$\sqrt{D}$)/2= (9+1)/2a=10/2=5   x2=5

b) Δ=b²-4ac=1-(-2)*4=1+8=9   x1=(-1-3)/2= -4/2=-2   x1=-2

x2= (-1+3)/2= 2/2=1   x2=1

c) Δ=b²-4ac= 16-12=4  x1=(4-2)/2= 2/2=1  x1=1

x2= (4+2)/2= 6/2 =3   x2=3

d) Δ= 1- (-1)*2*4= 1+8=9   x1=(-1-3)/4=-4/4= -1   x1=-1

x2=(-1+3)/4=2/4=1/2  x2=1/2

e) Δ= 16-3*4=16-12=4    x1=(-4-2)/6= -6/6=-1   x1=-1

x2=(-4+2)/6=-2/6= -1/3    x2=-1/3

2. a) x(x-3)=0    x1=0  x2=3

b) 2x(x+2)=0  2x=0  x1=0   x+2=0  x2=-2

c) x(3x-4)=0    x1=0   3x=4   x2=4/3

3. a) (x-2)(x+2)=0    x-2=0  => x1=2   x+2=0  x2=-2

b) (x-3)(x+3)=0     x-3=0  x1=3   x+3=0  x2=-3

c) impartim la 2  (x²-4)=0   (x-2) (x+2)=0   x1=2  x2=-2