Question 1096609
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HINT: this value of x and this value of "a" form the vertex of the given parabola.


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    {{{x^2 + 4x  - 31}}} = {{{(x+2)^2 - 4 - 31}}} = {{{(x+2)^2 - 35}}}.


    So, this value of "a" is  a = -35,  and this value of "x" is  x = -2.
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