1) a-b+2c (a-b)

2) by+3b+2cy+6c

3) kl-5l-k+5

4) 3ab-2ac+4cd-6bd

5) y2-2by+6b-3y

y2 это y во 2 степени

1) a-b+2c (a-b) = (a-b) (1+2c)

2) by+3b+2cy+6c = (by+2cy) + (3b+6c) = y (b+2c) + 3 (b+2c) = (b+2c) (y+3)

3) kl-5l-k+5 = k (l-1) - 5 (l-1) = (l-1) (k-5)

4) 3ab-2ac+4cd-6bd = (-2ac+4cd) + (3ab-6bd) = 2c (2d-a) - 3b (2d-a) = (2d-a) (2c-3b)

5) y^2-2by+6b-3y = y (y-2b) + 3 (2b-y) = (y-2b) (y-3)