\(\left(x^2+y^2-5\right)-\left(2xy-4\right)^2=\left(x^2+y^2-1-2xy\right)^2=\left[\left(x-y\right)^2-1\right]^2=\left(x-y-1\right)^2\left(x-y+1\right)^2\)

cái này là pt đa thức thành nt

(x²+1)²-6(x²+1)²+5

=  (x²+1)²(-6+1)+5

= -5(x²+1)²+5

= -5(x⁴+2x²+1-1)

= -5(x⁴+2x²)

= -5x⁴-10x²

\(\left(x^2+1\right)^2-6\left(x^2+1\right)^2+5\\ \Leftrightarrow\left(x^2+1\right)\left(-6+5\right)\\ \Leftrightarrow\left(x^2+1\right).-1\\ \Leftrightarrow-x^2-1\)

Đề sai à bn

đề tui đúng mà

Lời giải:

$x^3-6x^2+12x-8=0$

$\Leftrightarrow (x-2)^3=0$

$\Leftrightarrow x-2=0$

$\Leftrightarrow x=2$

\(x^3-6x^2+12x-8=0\)

`<=>x^3-3.x^3.2+3.x.2^2-2^3=0`

`<=>(x-2)^3=0`

`<=>x-2=0`

`<=>x=2`

\(x^3+9x^2+27x+27=0\)

\(\Leftrightarrow x^3+3.x^2.3+3.x.3^2+3^3=0\)

\(\Leftrightarrow\left(x+3\right)^3=0\)

`<=>x+3=0`

`<=>x=-3`

\(x^3+9x^2+27x+27=0\)

\(\Leftrightarrow x^3+3.3.x^2+3.9x+3^3=0\)

\(\Leftrightarrow\left(x+3\right)^3=0\)

\(\Rightarrow x+3=0\Rightarrow x=-3\)

hat you ai im mai tơ im yến i 8 qua yu leo tần yes o no yes ok mai ơ tơ like ok 

\(x^3+3x^2+3x+1=0\\ \left(x+1\right)^3=0\\ x+1=0\\ x=-1\)

giúp vs

1 Tom didn't fix the refrigerator last monday

2 did her husband put a bunch of flowers on her desk?

3 she wasn't helping her dad at 11 am yesterday

4 were most of them safe after the accident?

5 he wasn't making any hot chocolate at 1:30 this morning

6 was I looking for my watch when the phone rang?

7 were you so scared when we heard a strange sound?

8 Anna didn't eat a lot of pizza at the party last night

9 did the doctor wash her hands after touching the patients?