Question

-x nhân x trừ 8 nhân x=26

Answer 1

Ta có : -x.x - 8x = 26

=> -x.x - 4x - 4x - 16 = 10

=> -x(x + 4) - 4(x + 4) = 10

=> -(x + 4)² = 10

=> \(x\in\varnothing\)

Answer 2

-x.x - 8x = 26

<=> -x² - 8x - 16 = 10

<=> -x² - 4x - 4x - 16 = 10

<=> -x( x + 4 ) - 4( x + 4 ) = 10

<=> ( -x - 4 )( x + 4 ) = 10

<=> -[( x + 4 )]( x + 4 ) = 10

<=> -( x + 4 )² = 10 

\(-\left(x+4\right)^2\le0\forall x\)=>  -( x + 4 )² = 10 * vô lí *

<=> x = \(\varnothing\)