Railways PYQCBT 1 2016

RRB NTPC · प्रश्न 1

(x^2 - x - 132) चे अवयव शोधा.

  1. (x - 11)(x - 12)

  2. (x + 12)(x - 11)

  3. (x + 11)(x + 12)

  4. (x - 12)(x + 11)

उत्तर दाखवा आणि स्पष्टीकरण

उत्तर: (D) (x - 12)(x + 11)

स्पष्टीकरण

To factorise x² − x − 132, find two numbers whose product is −132 and whose sum is −1 (the coefficient of x). These are −12 and +11, since −12 × 11 = −132 and −12 + 11 = −1. So x² − x − 132 = (x − 12)(x + 11).