Question

разложите на множители (x-1)(x+1)+(x-3)(x+1)

Answer 1

(  x - 1 )( x + 1 ) + ( x - 3 )( x + 1 ) = ( x + 1 )*( x - 1 + x - 3 ) = ( x + 1 )( 2x - 4 )