y is directly proportional to the positive square root of( x+2)² when x = 8 y= 250 find y when x = 4​

150

Step-by-step explanation:

Since y is directly proportional to sqrt((x+2)^2), there is a constant,k, such that

y=ksqrt((x+2)^2)

We are given a pair (x,y) in this relation. Let's plug in (8,250 ) to find k.

250=ksqrt((8+2)^2)

250=ksqrt((10)^2)

250=k10

250/10=k

25=k

So for any pair (x,y) we have the relation y=25((x+2)^2).

We are asked to find y when x=4.

y=25((4+2))^2

y=25(6)

y=150

Test to see if y is proportional to sqrt((x+2)^2)

For the given points: 250/150=10/6

The equation is true so we're great.

equal to

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