Разложите на множители: 1) m-n-m+n2) c+d-c+d3) 16x-25y-4x-5y4) 12ab+3ab+16b-a5) 49c-14c+1-21ac+3a6) ax+ay+x4+2xy+y

1. m - n - m + n = 1) (m - n) - (m - n) =

 (m - n) * (m + n) - (m - n) = (m - n) * (m + n - 1);

2. c + d - c + d = (c + d) - (c - d) = (c + d) - (c + d) * (c - d) = (c + d) * (1 - c + d);

3. 16x-25y-4x-5y = (16x-25y) - (4x+5y) = 

(4x+5y)*(4x-5y) - (4x+5y) = (4x+5y)*(4x-5y-1);

4. (12 * a * b) + (3 *a * b) + (16 * b) - a =

(12 *a *b + 3 * a * b) + (16 * b - a) =

 3 *a *b * (4 * b + a) + (4 *b + a) * (4 * b-a) =

(4 * b + a) * (3 *a *b + 4 * b - a);

5. 49 * c - 14 * c + 1 - 21 *a * c + 3 * a =

(49 * c - 14 * c + 1) - (21 * a *c - 3 * a) =

(7c-1) - 3a*(7c-1) = (7c-1)*(7c-3a-1);

6. a * x + a *y + x + 2 * x * y + y =

(a * x + a * y) + (x + 2 * x * y + y) =

a * (x + y) + (x + y) =

 (x + y) * (x + y + a).