Question

Descompuneti in factori:
a)7x(6x-5)^2-(4x-3)(6x-5)-2(6x-5)^2
^2 inseamna la a 2a

b)5x(5x-2)-2(5x-2)-9

Answer 1

a)

7x(6x-5)² - (4x-3)(6x-5) - 2(6x-5)² =

= (6x - 5)[7x(6x-5) - (4x-3) - 2(6x-5)]

= (6x - 5)(42x² - 35x - 4x + 3 - 12x + 10)

= (6x - 5)(42x² - 51x + 13)

b)

5x(5x-2) - 2(5x-2) - 9 =

= (5x - 2)(5x - 2) - 9

= (5x - 2)² - 9

= (5x - 2 - 3)(5x - 2 + 3)

= (5x - 5)(5x + 1)