Answer:
6 + 3[tex]\sqrt{10\\}[/tex] or 6 - 3[tex]\sqrt{10\\}[/tex]
Step-by-step explanation:
x^2 - 12x + 36 = 90
x^2 - 12x - 54 = 0
x = [tex]\frac{-b +/- \sqrt{b^{2} + 4ac }}{2a}[/tex]
a = 1, b= -12, c= -54
6 + 3[tex]\sqrt{10\\}[/tex] or 6 - 3[tex]\sqrt{10\\}[/tex]