



 
Hi Kevin, The key hear is the general quadratic. If $ax^2 + bx + c = 0$ then x is given by \[x = \frac{b \pm \sqrt{b^2  4 a c}}{2a}.\] If $b^2  4 ac >0$ then the square root gives you two solutions, one with the plus sign and the other with the minus sign. If $b^2  4 ac <0$ then the square root does not yield a real number and hence there are no real solution. If $b^2  4 ab = 0$ then there is one solution. Penny  


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