If x is real, find the maximum value of the expression -2x^2 + 7x + 9. Select the correct option
A) 6.125 B) 9.125 C) 12.125 D) 15.125 E) 18.125
This is an equation of a downward facing parabola.   The maximum value is the top point of the parabola.   -2x^2+7x+9 = (-2x+9)(x+1)   The roots are 9/2 and -1.   The maximum value must be when x is halfway between these two points.   x = 1.75   The maximum value is -2(1.75)^2+7(1.75)+9 = 15.125   The answer is 15.125.
<result>D</result>
If x is real, find the maximum value of the expression -2x^2 + 7x + 9.