Factor completely

Ex) 2x^2 + 5x -3: (2x -1) (x+3)
6) 2x^2 + x -10: ___ ____

1 answer

To factor the quadratic expression \(2x^2 + x - 10\), we can follow these steps:

  1. Multiply the leading coefficient (2) by the constant term (-10): \[ 2 \times -10 = -20 \]

  2. Find two numbers that multiply to -20 and add up to the middle coefficient (1): The numbers that satisfy this are 5 and -4 because: \[ 5 \times -4 = -20 \quad \text{and} \quad 5 + (-4) = 1 \]

  3. Rewrite the middle term using these two numbers: \[ 2x^2 + 5x - 4x - 10 \]

  4. Group the terms: \[ (2x^2 + 5x) + (-4x - 10) \]

  5. Factor out the common factors from each group: \[ x(2x + 5) - 2(2x + 5) \]

  6. Notice that \(2x + 5\) is a common factor: \[ (2x + 5)(x - 2) \]

Thus, the completely factored form of \(2x^2 + x - 10\) is: \[ (2x + 5)(x - 2) \]