Question 144827

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



From {{{2x^2+5x+5}}} we can see that {{{a=2}}}, {{{b=5}}}, and {{{c=5}}}



{{{D=(5)^2-4(2)(5)}}} Plug in {{{a=2}}}, {{{b=5}}}, and {{{c=5}}}



{{{D=25-4(2)(5)}}} Square {{{5}}} to get {{{25}}}



{{{D=25-40}}} Multiply {{{4(2)(5)}}} to get {{{(8)(5)=40}}}



{{{D=-15}}} Subtract {{{40}}} from {{{25}}} to get {{{-15}}}



Since the discriminant is less than zero, this means that there are two complex solutions