Question

Rezolvaţi ecuaţiile:
(3x -8)(x-2)=0
(3x-2)² + (4-6x)²
x² + (x +1)² =25

Answer 1

3x-8=0 sau x-2=0
x=8/3 sau x=2

x^2+x^2+2x+1=25
2x^2+2x+1-25=0
2x^2+2x-24=0
x^2+x-12=0
x=-4 sau x=3

Answer 2

(3x -8)(x-2)=0
3x-8=0
3x=8
x₁=8/3
x-2=0
x₂=2
S={2,8/3}
 
(3x-2)² + (4-6x)²=
9x²-12x+4+16-48x+36x²=0
45x²-60x+20=0        :5
9x²-12x+4=0
Δ=144-144=0
x₁=x₂=12/9=4/3
s={4/3}

x² + (x +1)² =25
x²+x²+2x+1=25
2x²+2x+1-25=0
2x²+2x-24=0     :2
x²+x-12=0
Δ=1+48=49
x₁=(-1+7)/2=3
x₂=(-1-7)/2=-4
S={-4,3}