Question

(3- a ) ( 3a + 4) ( a - 5)

Answer 1

(3 - a)(3a + 4)(a - 5)
= (9a + 12 - 3a² - 4a)(a - 3)
= (-3a² + 5a + 12)(a - 3)
= - 3a³ + 5a² + 12a + 9a² - 15a - 36
= - 3a³ + 14a² - 3a - 36

Answer 2

((3-a).(3a+4)).(a-5)
= (3.3a+3.4+(-a).3a+(-a).4).(a-5)
= (9a²+12-3a²-4a).(a-5)
= (9a²-3a²-4a+12).(a-5)
= (6a²-4a+12).(a-5)
= 6a².a+6a².(-5)+(-4a).a+(-4a).(-5)+12.a
+12.(-5)
= 6a^3-30a²-4a²+20a+12a-60
= 6a^3-34a²+32a-60