Which of the following is a solution of 2x² + 5x − 12 = 0?

Correct answer: 3/2. Factorising gives (2x − 3)(x + 4) = 0, so x = 3/2 or x = −4. Of the options, 3/2 is a solution.

Background: Split the middle term: 2x² + 8x − 3x − 12.

• −2: x = −2 does not satisfy the equation.
• −3/2: x = −3/2 does not satisfy the equation.
• −1/2: x = −1/2 does not satisfy the equation.

Did you know? The other root, −4, is not in the options.

Memory trick: Product ac = −24; sum = 5.