Multiple choice

If $-2$ is a root of the quadratic equation $ x^{2}+3x+p=0 $, then the roots are

  1. $0,-2$
  2. $-1,-2$
  3. $-2,1$
  4. $-1,1$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

If -2 is a root, then (-2)^2 + 3(-2) + p = 0, so 4 - 6 + p = 0, which means p = 2. The equation is x^2 + 3x + 2 = 0. Factoring gives (x+1)(x+2) = 0, so the roots are -1 and -2.

AI explanation

Substitute x = -2 into the equation x^2 + 3x + p = 0 to find p. This gives (-2)^2 + 3(-2) + p = 0, which simplifies to 4 - 6 + p = 0, meaning p = 2. The equation is now x^2 + 3x + 2 = 0. Factoring this quadratic equation gives (x + 1)(x + 2) = 0, so the roots are -1 and -2.

Keep practicing — related questions