Multiple choice

\begin{array} { l } { \text { If } 1 - p \text { is a root of quadratic equation } } { x ^ { 2 } + p x + ( 1 - p ) = 0 \text { , then the roots are } } \end{array}

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

If 1-p is a root, substitute x = 1-p into the equation: (1-p)^2 + p(1-p) + (1-p) = 0. Factor out (1-p): (1-p)(1-p + p + 1) = 0, which is (1-p)(2) = 0, so p = 1. If p = 1, the equation becomes x^2 + x = 0, so x(x+1) = 0. The roots are 0 and -1.

AI explanation

Substitute x = 1 - p into the quadratic equation x^2 + px + (1 - p) = 0. This gives (1 - p)^2 + p(1 - p) + (1 - p) = 0, which factors to (1 - p)(1 - p + p + 1) = 0. Solving this yields (1 - p)(2) = 0, meaning p = 1. Substituting p = 1 back into the original equation gives x^2 + x = 0, which factors as x(x + 1) = 0, resulting in the roots 0 and -1.