Respuestas:
1) x=-51
2)[tex]x_{1}[/tex]=-1, [tex]x_{2}[/tex]=21
3) x=1
Explicación paso a paso:
1)
3[tex]x^{2}[/tex] +2601-2[tex]x^{2}[/tex]+102x=0
[tex]x^{2}[/tex]+2601+102x=0
[tex]x^{2}[/tex]+102x+2601=0
(x+51)²=0
x+51=0
x=-51
2)
[tex]x^{2}[/tex]-21-20x=0
[tex]x^{2}[/tex]-20x-21=0
[tex]x^{2}[/tex]+x-21x-21=0
x(x+1)(x-21)=0
(x+1)(x-21)=0
x+1=0
x-21=0
x=-1
x=21
3)
2x-[tex]x^{2}[/tex]=1
2x-[tex]x^{2}[/tex]-1=0
-([tex]x^{2}[/tex]-2x+1)=0
-(x-1)²=0
(x-1)²=0
x-1=0
x=1
