Question 199285

From {{{14x^2-9x-7}}} we can see that {{{a=14}}}, {{{b=-9}}}, and {{{c=-7}}}



{{{D=b^2-4ac}}} Start with the discriminant formula.



{{{D=(-9)^2-4(14)(-7)}}} Plug in {{{a=14}}}, {{{b=-9}}}, and {{{c=-7}}}



{{{D=81-4(14)(-7)}}} Square {{{-9}}} to get {{{81}}}



{{{D=81--392}}} Multiply {{{4(14)(-7)}}} to get {{{(56)(-7)=-392}}}



{{{D=81+392}}} Rewrite {{{D=81--392}}} as {{{D=81+392}}}



{{{D=473}}} Add {{{81}}} to {{{392}}} to get {{{473}}}



Since the discriminant is greater than zero, this means that there are two real solutions.