If two circles are concentric then
a) they will have the same area.
b) they will have the same center.
c) they will have the same radius length, but different diameter length.
d) they will have the same diameter length, but different radius length.

two circles are concentric when they will have the same centre

no he doesnt because "-16' is negatiive

step-by-step explanation:

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