Question 290245
9a^2+42a-49
 {{{a = (-b +- sqrt( b^2-4*a*c ))/(2*a) }}} 
a=(-42+-sqrt[42^2-4*9*-49])/2*9
a=(-42+-sqrt[1764+1764])/18
a=(-42+-sqrt3528)/18
a=(-42+-59.397)/18
a=(-42+59.397)/18
a=17.397/18
a=.9665 ans.
a=(-42-59.397)/18
a=-101.397/18
a=-5.633 ans.