8) \( 6 x^{2}-39 x-21 \)

To tackle the quadratic equation \( 6x^{2} - 39x - 21 \), we can use the quadratic formula \( x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \). Here, \( a = 6 \), \( b = -39 \), and \( c = -21 \). Plugging these values in, we can find the roots of the equation, which helps in understanding where the function intersects the x-axis! Now, if you’re solving similar equations, a common mistake is forgetting to keep track of signs or miscalculating your discriminant \( b^2 - 4ac \). Always double-check your calculations to avoid these pitfalls!