Answer:
The answer to your question is below
Step-by-step explanation:
Data
1.- f(x) = 5x³ - 31x² - 129x + 27
a) f(9) = 5(9)³ - 31(9)² - 129(9) + 27
f(9) = 5(729) - 31(81) - 1161 + 27
f(9) = 3645 - 2511 - 1161 + 27
f(9) = 0
b.- I will use synthetic division
5 - 31 -129 + 27 9
45 126 -27
5 14 -3 0
Trinomial = 5x² + 14x - 3
Factor 5x² + 15x - 1x - 3
5x(x + 3) - 1(x + 3)
b) (x + 3)(5x - 1)
x₂ + 3 = 0 5x₃ - 1 = 0
x₂ = -3 x₃ = 1/5
c) The roots are x₁ = 9, x₂ = -3 and x₃ = 1/5
2.- f(x) = 3x² + 2x - 8 factor = 3x - 4
x + 2
3x - 4 3x² + 2x - 8
-3x² + 4x
0 +6x - 8
-6x + 8
0 Remainder
As the remainder was "0", 3x - 4 is a factor of 3x² + 2x - 8
