Agrupamento:

b) 5ax - 5ay + bx - by =

5a(x - y) + b(x - y) =

(5a + b) (x - y)

d) 6a² + 2ab - 3ac - bc =

6a² - 3ac + 2ab - bc =

3a(2a - c) + b(2a - c) =

(3a + b)(2a - c)

f) x⁴ - x³ - 9x + 9 =

x³(x - 1) - 9(z - 1) =

(x³ - 9)(x - 1)

h) bx² - 2by + 5x² - 10y =

x²(b + 5) -2y(b + 5) =

(x² - 2y)(b + 5)

j) cx + x +c + 1 =

x(c + 1) + 1(c + 1) =

(x + 1)(c + 1)