The idea is we do some, you learn how to do them, and you do the rest. Last quadratic equation for you. Please ask questions if you're confused.
On this one I'll teach you a shortcut called the Shakespeare Quadratic Formula (2b or -2b):
[tex]x^2 - 2bx + c \textrm{ has zeros } x=b \pm \sqrt{b^2-c}[/tex]
Let's do our problem.
[tex] x^2 - 8x + 16 = 11[/tex]
[tex]x^2 - 8x + 5 = 0 [/tex]
Shakespeare Quadratic formula time; we have a -8x so b=4:
[tex]x = 4 \pm \sqrt{4^2-5}= 4\pm \sqrt{11}[/tex]
Answer: B C
