How do you solve #x^2+10x+9=0# using the quadratic formula?

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Answer 1 · 2014-10-25T17:57:01

#x = (-b +- root 2 (b^2 - 4ac))/(2a)#

where #a#, #b#, and #c# are the coefficients of the terms of the quadratic equation

For your equation we have

#x^2 + 10x + 9 = 0#

#=> x = (-10 +- root 2 (10^2 - 4(1)(9)))/(2(1))#

#=> x = (-10 +- root 2 (100 - 36))/(2)#

#=> x = (-10 +- root 2 64) / 2#

#=> x = (-10 +- 8)/2#

#=> x = (-10 + 8)/2, x = (-10 - 8)/2#

#=> x = -1, x = -9#