Question

Find the value of k if x = 4 is the solution of the equation 3x² + kx $-$2 = 0

Answer 1

Given: x = 4 is the solution of the quadratic equation 3x² + kx – 2 = 0.
Thus, x = 4 satisfies the given equation.
=> 3(4)² + k(4) – 2 = 0
=> 3 × 16 + 4k – 2 = 0
=> 48 + 4k – 2 = 0
=>4k + 46 = 0
=> k = $\frac{-23}{2}$