Question 1047876

{{{7x(x+3)-9=17x-8}}}


{{{7x^2+21x-9=17x-8}}}


{{{7x^2+21x-9-17x+8=0}}}


{{{7x^2+4x-1=0}}}-> note: {{{a=7}}},{{{b=4}}}, and {{{c=-1}}}


{{{x = (-b +- sqrt( b^2-4*a*c ))/(2*a) }}} 


{{{x = (-4 +- sqrt(4^2-4*7*-1 ))/(2*7) }}} 


{{{x = (-4 +- sqrt(16+28 ))/14 }}} 


{{{x = (-4 +- sqrt(44 ))/14 }}} 


{{{x = (-4 +- sqrt(11*4 ))/14 }}} 


{{{x = (-4 +- 2*sqrt(11 ))/14 }}} 


{{{x = (-cross(4)2 +- cross(2)*sqrt(11 ))/cross(14)7 }}} 


{{{x = (-2 +- sqrt(11 ))/7 }}} 


{{{x = (-2/7 +- sqrt(11 )/7 )}}} 


solutions:

{{{x = -2/7 + sqrt(11 )/7 }}} 

{{{x = -2/7 - sqrt(11 )/7 }}}