If $x=2$ is a root of the quadratic equation $x^2-kx+8=0$, find the value of $k$.

Step-by-step solution

1. Substitute $x=2$ into the equation: $2^2-k(2)+8=0$.
2. Compute $4-2k+8=0$ which simplifies to $12-2k=0$.
3. Solve for $k$: $2k=12$ giving $k=6$.
4. Thus the required value of $k$ is $6$.

Concept tested: Using a given root to find coefficient

Published 4 October 2026 · How this solution was prepared and checked