Question 185387
{{{o(x) = 5x - x^2}}}
This is a quadratic equation that is in the shape of a parabola. You will need to plot several points in order to get the shape correct. Note the sign on the x^2 term is negative. So the "U shape" is pointed down.
Pick a value of x, then solve for it
x = 0. o(0) = 5*5 - x^2 = 0 . so one point is (0,0)
x = 1. o(10 = 5*1 -1^2 = 5-1 = 4. Another point is (1,4)
and so on. 

Then plot the points and draw the curve. Again geogebra is a nice tool to do this
{{{graph(400,400,-10,10,-10,10, 5x-x^2)}}}