Factoring

1. Factor a common factor out of 4x³ - 6x² + 12x .
2. Factor a common factor out of 6x³y² + 15x²y⁵ -30x⁷y⁴z .
3. Factor 16y² - 9 as a difference of two squares.
4. Factor 4x¹⁶ - 9 y⁶ as a difference of two squares.
5. Factor (y -2)² - 9 as a difference of two squares.
6. Factor the trinomial 6x² + 7x - 20.
7. Factor the trinomial 16x² - 8x + 1.
8. Factor the trinomial 3x² -5x + 2.
9. Factor 64x³ - y⁶ as a difference of two cubes.
10. Factor 27x⁹ + y²⁷ as a sum of two cubes.
11. Factor x³ - x² + 3x - 3 by grouping.
12. Factor 3a³ +3a² - 27a - 27 by grouping.
13. Factor x² + 4x + 4 - 9y² by grouping.

Completely factor the expression.

14. 45a² + 38ab + 8b²
15. x⁴ - 64y²
16. a⁶ - 64 b³
17. (y² + 8)² - 36y²
18. 216a⁹ + 125b⁶
19. 6 + 2y - 3y³ - y ⁴
20. y ⁶ + 7y ³ - 8