Разложите на множители а) b²-c²-b+c= б) a+b-a²+b²= в) a²-a-c²+c= г) m-m²-n+n²=

1) ( b - c)( b + c) - ( b - c) = ( b - c)(b + c - 1)
2) ( b + a) + ( b - a)(b + a) = ( a + b)(1 - a + b)
3) ( a - c)(a+ c) - ( a - c) = ( a - c)( a + c - 1)
4)( n -m)(n +m) + ( m -n) = ( n - m)(n + m) - ( n -m) = ( n -m)(n + m - 1)