Question 277941
The graph of {{{P=-2x^2+20x-2}}} is a parabola (because of the x squared) which opens downward (because of the minus in front of the x squared). It looks like this:
{{{graph(300, 300, -5, 50, -5, 50, -2x^2+20x-2)}}}
The maximum of P will be at the vertex of the parabola. So we want to find the x coordinate of the vertex.<br>
For a parabola in the form {{{y = ax^2 + bx + c}}}, the x coordinate of the vertex is (-b)/2a. Since your b is 20 and your a is -2, the x coordinate of the vertex will be:
{{{(-(20))/2(-2) = (-20)/(-4) = 5}}}<br>
So the answer is (d) 5 units.