Question

Please Help!!!

Answer 1

Let's use the quadratic formula
$\frac{ - b( + - ) \sqrt{ {b}^{2} - 4ac} }{4a}$
a = 1, b = 0, c = -18
$\frac{ - (0)( + - ) \sqrt{ {(0)}^{2} - 4(1)( - 18)} } {4(1)} \\ \frac{( + - ) \sqrt{72} }{4}$
This is now split into two equations:
$\frac{ + \sqrt{72} }{4}$
and
$\frac{ - \sqrt{72} }{4}$
Since$\frac{ \sqrt{72} }{4} \\ = \frac{6 \sqrt{2} }{4} \\ = \frac{3 \sqrt{2} }{2}$
The answer is
$\frac{3 \sqrt{2} }{2} \: and \: \frac{ - 3 \sqrt{2} }{2}$
which means there are 2 real number solutions to the problem: answer B.