Bobby will buy coffe and hot chocolate for his co-workers each cup of coffe costs $2.25 and each cup of hot chocolate costs $1.50 .he pays a total of $15.75 for 8 cups
( answer me as quickly as possible)

i dont get it. where are the "descriptions"?

answer: 204

step-by-step explanation:

we are told that the revenue is

x⋅(4080−10x)=−10x^2+4080x

this is a quadratic function, so to maximize it we should find the x-value of its vertex. recall that the x-value of the vertex of the parabola ax^2+bx+c is given by the formula −b/2a.

so in this case, we have a=−10 and b=4080, so the x-value of the vertex is

−b/2a= −(4080)/2(−10)=204