9. GIVEN: y(x + 1) = 51; y = 3 PROVE: x = 16

see explanation

Step-by-step explanation:

y(x + 1) = 51 ← substitute y = 3 into the equation

3(x + 1) = 51 ( divide both sides by 3 )

x + 1 = 17 ( subtract 1 from both sides )

x = 16

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