book Maths Puzzle Numerical Ability

The degree three polynomial f(x) with real coefficients and leading
coefficient 1, has 4 and 3 + i among its roots. Express f(x) as a
product of linear and quadratic polynomials

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book Other Question

(6 -3) (1 6)
-
(4 11) (-3 14)

Please tell me what is the difference.
what are these things i can never get them right??