Find the value of x when y=13 (show work)

x = -3

Step-by-step explanation:

First, we want to sub in the numbers then isolate the variable. We subtract 4 from both sides. That gives us 13 - 4 = -3x which equals 9 = -3x. Now we divide both sides by -3. So x equals -3. I hope this helps! Please make me the brainliest! Thanks!

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