A polynomial in x whose roots are 4/3 and -3/5 is?
-
15x2 - 11x – 12
- 15x2 + 11x – 12
- 12x2 - x – 12
- 12x2 + 11x – 15
The correct answer is: A
Explanation
If 4/3 and -3/5 are roots of a polynomial
Imply x = 4/3 and - 3/5
3x = 4 and 5x = -3
∴3x-4 = 0 and 5x+3 = 0 are factors
(3x-4)(5x+3) = 0 product of the factors
15x2 + 9x – 20x – 12 = 0 By expansion
15x2 - 11x – 12 = 0
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