Question

x square - x minus 21

Answer 1

Solution:-

guven by:-

${x}^{2} - x - 21 \\ by \: formula \\ \frac{ - b( + - ) \sqrt{ {b }^{2} - 4ac } }{2a} \\ \\ \frac{1 ( + - ) \sqrt{1 + 84} }{2} \\ \frac{1 ( + - ) \sqrt{85} }{2} \\ x = \frac{1 + \sqrt{85} }{2} \\ x = \frac{1 - \sqrt{85} }{2}$
☆i hope its help☆