waecmaths question:
If the sum of the roots of the equation $(x-p)(2x+1)=0$ is 1. find the value of p
Option A:
$1\tfrac{1}{2}$
Option B:
$\tfrac{1}{2}$
Option C:
$-\tfrac{1}{2}$
Option D:
$-1\tfrac{1}{2}$
waecmaths solution:
$\begin{align} & (x-p)(2x+1)=0 \\ & 2{{x}^{2}}+x-2px-p=0 \\ & 2{{x}^{2}}+(1-2p)x-p=0 \\ & {{x}^{2}}+\frac{(1-2p)}{2}x-\frac{p}{2}=0 \\ & \text{Sum of roots } \\ & \frac{1-2p}{2}=1 \\ & 1-2p=2 \\ & p=-\frac{1}{2} \\\end{align}$
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