Home › RRB Group D › Mathematics › Polynomials and HCF › Find the HCF of 15x² + 8x - 12, 3x² + x - 2, 3x²…
Find the HCF of 15x² + 8x - 12, 3x² + x - 2, 3x² - 2x and 9x² - 12x + 4.
A3x - 4
Bx - 2
C3x - 2
Dx - 4
Answer & Solution
Correct answer: C. 3x - 2
1. Factorise each: 15x² + 8x - 12 = (3x - 2)(5x + 6); 3x² + x - 2 = (3x - 2)(x + 1).
2. Also 3x² - 2x = x(3x - 2); 9x² - 12x + 4 = (3x - 2)².
3. The factor common to all four is (3x - 2).
4. So the HCF is 3x - 2.
_Source: RRB Group D CEN-02/2018 PYQ, Q.74._