The surface area of which composite figure is the sum of the areas of eight triangular faces? two rectangular pyramids joined at their congruent bases
two rectangular pyramids joined at two congruent lateral faces
two triangular prisms joined at their congruent bases
two triangular prisms joined at two congruent lateral faces

5 x 14?

im new, sorry if this is wrong.

step-by-step explanation:

answer is x<

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