(х+2)(3х²+7х+1)=х²-4

Question

(х+2)(3х²+7х+1)=х²-4

Answer 1

( Х + 2)( 3х^2 + 7х + 1 ) = х^2 - 4
( Х + 2)( 3х^2 + 7х + 1 ) - ( Х + 2 )( Х - 2 ) = 0
( X + 2 )( 3x^2 + 7x + 1 - ( X - 2 )) = 0
( X + 2 )( 3x^2 + 6x + 3 ) = 0
X + 2 = 0
X = - 2
3x^2 + 6x + 3 = 0
3( x^2 + 2x + 1 ) = 0
( X + 2 )^2 = 0
X = - 2
Ответ ( - 2 )