What variable expression represents the phrase "25 decreased by the sum of 6 and a number"?

a- 25-6+n
b- (6+n)-25
c- 25-(6+n)
d- 25+6-n

just take the area of the square and then the area of the circle then subtract the circle area from the squares area

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