The quotient of open paren x to the 4th power plus 5 x cubed minus 3 x minus 15 close paren and open paren x cubed minus 3 close paren is a polynomial. What is the quotient?

Group the terms in the numerator: x⁴ + 5x³ − 3x − 15 = x³(x + 5) − 3(x + 5). Factoring out the common factor (x + 5) gives (x + 5)(x³ − 3), so dividing by x³ − 3 leaves the quotient x + 5, choice B.

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