Find the roots of the quadratic equation:
\$ (x-6)(x-1) = 9 \$

Now converted to

\$ax^2+bx+c=0\$

after converting

\$ x^2 - 7x + 6 - 9 = 0 \$

by simplifying

\$x^2 - 7x - 3 = 0\$

Since the equation is in the form of

\$ax^2+bx+c=0\$

formula

\$ x = (-b \pm \sqrt (b^2 - 4ac))/(2a) \$

Substitute the values

\$ a = 1, b = -7 , c = -3\$

converting the equation into formula by substituting the values

\$ x = (-(-7) \pm \sqrt ((-7)^2 - 4(1)(-3)))/(2(1)) \$

Simplifing the equation

\$ x = (7 \pm \sqrt (49 + 12))/2 \$

We know that [i^2 = -1]

\$ x = (7 \pm \sqrt (61))/2 \$

After simplification we get

\$ x = (7 + \sqrt (61))/2 , (7 - \sqrt (61))/2 \$

Answer

C