Multiple choice

If one root of the quadratic $2x^2+px-4=0$ is $2$, then the value of $p$ will be:

  1. $-3$
  2. $-2$
  3. $2$
  4. $3$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

If x=2 is a root, then 2(2)^2 + p(2) - 4 = 0. This simplifies to 8 + 2p - 4 = 0, so 4 + 2p = 0, which means 2p = -4, so p = -2.

AI explanation

Since x = 2 is a root of the quadratic equation 2x^2 + px - 4 = 0, it must satisfy the equation when substituted for x. Substituting the value gives 2(2)^2 + p(2) - 4 = 0. Simplifying this yields 8 + 2p - 4 = 0, or 2p + 4 = 0. Solving for p gives 2p = -4, so p = -2.

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