Final answer:
To find the polynomial, use polynomial long division and set up the division as x³ - 3 | x⁴ + 5x³ - 3x - 15. Divide the first term of the dividend by the first term of the divisor, subtract the result, and repeat the process until the remainder is 0. The correct polynomial is x⁷ + 5x⁶ - 6x⁴ - 30x³ + 9x + 45, which corresponds to option a).
Step-by-step explanation:
To find the polynomial, we can use polynomial long division. Given that the quotient of (x4+5x3−3x−15) divided by a polynomial is (x3−3), we can set up the division as follows:
x³ - 3 | x4 + 5x³ - 3x - 15
First, divide the first term of the dividend by the first term of the divisor, which is x³ divided by x³. This gives us x. We then multiply the divisor by x to get x⁴ - 3x³. Subtract this from the dividend to get 8x³ - 3x - 15. Repeat the process until we have a remainder of 0. The final result is the polynomial x⁷ + 5x⁶ - 6x⁴ - 30x³ + 9x + 45. Therefore, the correct answer is option a).