Question

(x+1)(x2−x+1)−x×(x2−2)=19     giúp mik vs

Answer 1

`(x+1)(x^2-x+1)-x(x^2-2)=19`

`<=>x^3+1-x^3+2x=19`

`<=>2x+1=19`

`<=>2x=18`

`<=>x=9`

Vậy \(S=\left\{9\right\}\)

Answer 2

\(\Leftrightarrow x^3+1-x^3+2x=19\)

=>2x=18

hay x=9

 

Answer 3

\(\left(x+1\right)\left(x^2-x+1\right)-x.\left(x^2-2\right)=19\)

\(\Leftrightarrow x^3+1-x.\left(x^2-2\right)=19\)

\(\Leftrightarrow x^3+1-x^3+2x=19\)

\(\Leftrightarrow1+2x=19\)

\(\Leftrightarrow2x=19-1\)

\(\Leftrightarrow2x=18\)

\(\Leftrightarrow x=18:2\)

\(\Leftrightarrow x=9\)

Answer 4

$(x+1)({}^{}-x+1)-x({}^{}-2)=19$

$\iff {}^{}+1-{}^{}+2x=19$

$\iff 2x+1=19$

$\iff 2x=18$

$\iff x=9$

Vậy $S=\left\{9\right\}$

Answer 5

$\iff {}^{}+1-{}^{}+2x=19$

=>2x=18

hay x=9

Answer 6

$\left(x+1\right)\left({}^{}-x+1\right)-x.\left({}^{}-2\right)=19$

$\iff {}^{}+1-x.\left({}^{}-2\right)=19$

$\iff {}^{}+1-{}^{}+2x=19$

$\iff 1+2x=19$

$\iff 2x=19-1$

$\iff 2x=18$

$\iff x=18:2$

$\iff x=9$