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anonymous
 one year ago
please help!!!
anonymous
 one year ago
please help!!!

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DanJS
 one year ago
Best ResponseYou've already chosen the best response.0put it in standard form first ax^2 + bx + c = 0 c is negative 5, not plus 5

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0so the mistake starts from the first step?

Michele_Laino
 one year ago
Best ResponseYou've already chosen the best response.1hint: your equation is: \[{x^2} + 4x  5 = 0\]

Michele_Laino
 one year ago
Best ResponseYou've already chosen the best response.1yes! the right answer is: \[\begin{gathered} x = \frac{{  4 \pm \sqrt {{{\left( {  4} \right)}^2}  4 \times 1 \times \left( {  5} \right)} }}{{2 \times 1}} = \hfill \\ \hfill \\ = \frac{{  4 \pm \sqrt {16 + 20} }}{2} = \frac{{  4 \pm 6}}{2} = ...? \hfill \\ \end{gathered} \]

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0but i need to explain where the student went wrong

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0does she go wrong since the beginning because she put 5 instead of 5?

Michele_Laino
 one year ago
Best ResponseYou've already chosen the best response.1the student was wrong, since the coefficient c is 5 not +5

Michele_Laino
 one year ago
Best ResponseYou've already chosen the best response.1namely: \[\Large c =  5\] before applying the formula: \[\Large x = \frac{{  b \pm \sqrt {{b^2}  4 \times a \times c} }}{{2 \times a}}\] we have to write our quadratic equation, in this form: \[\Large a{x^2} + bx + c = 0\]

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0okay, thanks so much!! :)
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