Expand f (x) = (x - (2 + i)) (x - (2 - i)) (x - 5)

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Mathematics

Guest

10 January, 13:38

Expand f (x) = (x - (2 + i)) (x - (2 - i)) (x - 5)

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Popeye · Answer 1

F (x) = (x - (2 + i)) (x - (2 - i)) (x - 5)

f (x) = (x - 2 - i) (x - 2 + i) (x - 5)

f (x) = (x (x - 2 + i) - 2 (x - 2 + i) - i (x - 2 + i)) (x - 5)

f (x) = ((x2 - 2x + xi) + (-2x + 4 - 2i) + (-xi + 2i - i2) (x - 5)

f (x) = (x2 - 4x + 4 - i2) (x - 5)

f (x) = x (x2 - 4x + 4 - i2) - 5 (x2 - 4x + 4 - i2)

f (x) = (x3 - 4x2 + 4x - xi2) + (-5x2 + 20x - 20 + 5i2)

f (x) = x3 - 9x2 + 24x - 20 + (-x + 5) i2