Question

if A = x3, B = 4x2 + x – 1, C = x + 1, then find (A – B) (A – C).
Choose one:

x6 – 4x5 + 2x4 + 4x3 + 5x2 – 1

x6 – 4x5 – 2x4 + 4x3 + 5x2 – 1

x6 + 4x5 – 2x4 + 4x3 + 5x2 – 1

x6 – 4x5 – 2x4 – 4x3 + 5x2 – 1

Answer 1

A-B = X³ - 4X² - X +1
A-C = X³ - X - 1
NOW, (A-B) (A-C)
(x³ - 4x² - X + 1) ( x³ - X - 1)
x6 - x⁴ - x³ - 4x5 +4x³ + 4x² - x⁴ + x² + x + x³ - X - 1
X6 - 2x⁴ + 4x³ - 4x5 + 5x² - 1
X6 - 4x5 - 2x⁴ + 4x³ + 5x² - 1