Question

resolva as operações
a)(3i-12) x (2-3i)

Answer 1

(3i-12) x (2-3i)=
6i - 9i² x 36i - 24=
9i² - 30i -24 = 0
∆= b²- 4•a•c
∆= (-30)² - 4•9•(-24)
∆= 900 + 864= 1764
x= -b +- √∆
2a
x= -(-30)+-√1764
2• 9
x = 30+- 42 =
18
x'= 30+42= 72 = 4
18. 18
x"= 30-42= -12= -2
18. 18. 3