m” + 14m - 15
= m” + 15m - m - 15
= m( m + 15 ) - ( m + 15 )
= ( m - 1 )( m + 15 )
或者
= m" + 14m + 7" - 49 - 15
= ( m + 7 )" - 64
= ( m + 7 - 8 )( m + 7 + 8 )
= ( m - 1 )( m + 15 )
m” + 14m - 15
= m” + 15m - m - 15
= m( m + 15 ) - ( m + 15 )
= ( m - 1 )( m + 15 )
或者
= m" + 14m + 7" - 49 - 15
= ( m + 7 )" - 64
= ( m + 7 - 8 )( m + 7 + 8 )
= ( m - 1 )( m + 15 )