1-* 5x7 -15x6 +10x3 -20x2

R: (x-3)(10x2-5x6)


2-* 12y9-4y6+6y5+8y4

R: (Y-3)(12Y8-6Y4)

3-* 7x-14x3

R: (x-2)(7-x2)

4-* -3x3-18x6

R: (x-6)(-3x2-x4)

5-* 10y3-5y2+10y

R: (y-1)((10y2-10)

6-* 9y3-18y2+27y

R: (y-2)(9y2-27)

7-* 8x8+16x5-24x4+8x3

R: (+2)(8x7+24x3)

8-* 6x4+9x2+2x2+3

R: (x-2)(6x3-2x1)

9-* 12x4+8x2+3x2+2

R: (x-1)(12x3-3x1)

10-* x2+2y-2x2-4y

R: (x+2y)(x1+2x1)

11-* 3a4-6a2-2a2+4

R: (a-2)(3a3-2a1)

12-* 6x3-2x2+3x-1

R: (x-1)(6x2-3)

13-* 4x3+6x2+2x+3

R: (x-2)(4x2-2)

14-* 7x4-7x13-14x15

R: (x+1)(7x3+7x12)