Question

iv) 2x3 – 11x2+44x+27, if x = 25/3-4i​

Answer 1

Answer:

2x³ - 11x² + 44x + 27 = 2

Step-by-step explanation:

x = 25/3-4i​

=> x  = (25/(3 - 4i)  * (3 + 4i)/(3 + 4i)

=> x = (25(3 + 4i))/(9 - 16i²)

=> x = 25(3 + 4i)/(9 + 16)

=> x = 25(3 + 4i)/(25)

=> x = (3 + 4i)

2x³ - 11x² + 44x + 27

= x²(2x - 11) + 44x + 27

= (3 + 4i)² ( 2(3 + 4i) - 11)  + 44(3 + 4i) + 27

= (9 - 16 + 24i)(6 + 8i - 11)  + 132 + 176i + 27

= (24i - 7)(8i - 5) + 176i + 159

= ( -192 + 35 - 176i) +  176i + 159

= -192 + 194

= 2

2x³ - 11x² + 44x + 27 = 2