Which of the following are solutions?

Question

asked Aug 21, 2019 28.8k views

1 Answer

Basil Bourque · Answer 1 · 2019-08-26T01:10:34+0000

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):

$x^2 - 2bx + c \textrm{ has zeros } x=b \pm √(b^2-c)$

Let's do our problem.

x^2 - 8x + 16 = 11

x^2 - 8x + 5 = 0

Shakespeare Quadratic formula time; we have a -8x so b=4:

$x = 4 \pm √(4^2-5)= 4\pm √(11)$

Answer: B C