Question

1). 2x²+5x+2=0
2). x²-12x+11=0
3).x²+6x+9=0​

Answer 1

Explicație pas cu pas:

1)2x²+5x+2=0

2x²+4x+x+2=0

2x(x+2)+(x+2)=0

(x+2)(2x+1)=0,

x+2=0, x=-2

2x+1=0, x=-1/2

2) x²-12x+11=0

x²-x-11x+11=0

x(x-1)-11(x-1)=0

(x-1)(x-11)=0

x-1=0, x=1

x-11=0, x=11

3)x²+6x+9=0

x²+3x+3x+9=0

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

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

x+3=0, x=-3