PLEASEE HELPP!!!
What is the mistake in setting up the quadratic formula?

Answer:
First, we bring the equation to the form ax²+bx+c=0, where a, b, and c are coefficients. Then, we plug these coefficients in the formula: (-b±√(b²-4ac))/(2a) . See examples of using the formula to solve a variety of equations.
That 6 should be -6
Let me solve it for you
[tex]\\ \rm\rightarrowtail 2x-x-6=0[/tex]
So
[tex]\\ \rm\rightarrowtail x=\dfrac{-b\pm \sqrt{b^2-4ac}}{2a}[/tex]
[tex]\\ \rm\rightarrowtail x=\dfrac{-(-1)\pm\sqrt{(-1)^2-4(2)(-6)}}{2(2)}[/tex]
[tex]\\ \rm\rightarrowtail x=\dfrac{1\pm \sqrt{1+48}}{4}[/tex]
[tex]\\ \rm\rightarrowtail x=\dfrac{1\pm 7}{4}[/tex]
[tex]\\ \rm\rightarrowtail x=\dfrac{8}{4}\:or\:\dfrac{-6}{4}[/tex]
[tex]\\ \rm\rightarrowtail x=2\:or\:\dfrac{-3}{2}[/tex]