6xcube-30xsquare+60x-48 and 3xcube-12square+21x-18
Answers
1: One common factor. a x + a y = a (x + y)
2: Sevearl grouped common factor. a x + a y + b x + b y = a(x + y) + b(x + y) = (a + b ) (x + y)
3: Difference of two squares (1). x 2 - y 2 = (x + y)(x - y)
4: Difference of two squares (2). (x + y) 2 - z 2 = (x + y + z)(x + y - z)
5: Sum of two cubes. x 3 + y 3 = (x + y)(x 2 - x y + y 2)
6: Difference of two cubes. x 3 - y 3 = (x - y)(x 2 + x y + y 2)
7: Difference of fourth powers. x 4 - y 4 = (x 2 - y 2)(x 2 + y 2) = (x + y)(x - y)(x 2 + y 2)
8: Perfet square x 2 + 2xy + y 2 = (x + y) 2
9: Perfet square x 2 - 2xy + y 2 = (x - y) 2
10: Perfect cube x 3 + 3x 2y + 3xy 2 + y 3 = (x + y) 3
11: Perfect cube x 3 - 3x 2y + 3xy 2 - y 3 = (x - y) 3
I hope you are understand my solution