Question 146569


{{{x^2+9x+7=0}}} Start with the given equation.



Let's use the quadratic formula to solve for x



{{{x = (-b +- sqrt( b^2-4ac ))/(2a)}}} Start with the quadratic formula



{{{x = (-(9) +- sqrt( (9)^2-4(1)(7) ))/(2(1))}}} Plug in  {{{a=1}}}, {{{b=9}}}, and {{{c=7}}}



{{{x = (-9 +- sqrt( 81-4(1)(7) ))/(2(1))}}} Square {{{9}}} to get {{{81}}}. 



{{{x = (-9 +- sqrt( 81-28 ))/(2(1))}}} Multiply {{{4(1)(7)}}} to get {{{28}}}



{{{x = (-9 +- sqrt( 53 ))/(2(1))}}} Subtract {{{28}}} from {{{81}}} to get {{{53}}}



{{{x = (-9 +- sqrt( 53 ))/(2)}}} Multiply {{{2}}} and {{{1}}} to get {{{2}}}. 



{{{x = (-9+sqrt(53))/(2)}}} or {{{x = (-9-sqrt(53))/(2)}}} Break up the expression.  



So our answers are {{{x = (-9+sqrt(53))/(2)}}} or {{{x = (-9-sqrt(53))/(2)}}} 



which approximate to {{{x=-0.86}}} or {{{x=-8.14}}}