Question 1184852
Maximum point at {{{f(-7/4)=59/2}}} so the range is the values y which less than or equal to 59/2 or 29.5


{{{f(x)=-2x^2-7x+5}}}
{{{-2(x^2+(7/2)x)+5}}}
You need to use {{{(7/4)^2}}} for completing-the-square.

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{{{f(x)=-2(x+7/4)^2+59/2}}}--------showing the vertex is maximum point for f, and range is {{{y<=59/2}}}.