What value of y would make {(-2, 18), (3, y), (6, 6), (-18, 2), (4, 9)} an inverse variation?

The value of "y" the would make the ordered pairs an inverse variation is;

y = 12

Step-by-step explanation:

The given ordered pairs are;

{(-2, 18), (3, y), (6, 6), (-18, 2), (4, 9)}

When a pair of variables, "x" and "y", vary inversely to one another, as the value of one variable increases, the value of the other variable decreases

Mathematically, we have;

y ∝ 1/x

The above relation can be represented as an equation as follows;

y = k/x

Where;

k = The constant of proportionality

Therefore, k = y·x

From the given ordered, we have;

k =  -2 × 18 = -36

k = 6 × 6 = 36

k = -18 × 2 = -36

k = 4 × 9 = 36

Therefore, the value of "k" is made constant as follows;

The inverse variation is y = k/(x × (-1)ⁿ)

Where;

n = The number of the term

Therefore, y = 36/(3 × (-1)²) = 12

y = 12

The given ordered pairs can therefore be written as follows;

{(-2, 18), (3, 12), (6, 6), (-18, 2), (4, 9)}.

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

starting with:    

5 + x - 12 = 2x - 7   

5 + x - 12 - x = 2x - 7 - x (subtract x from both sides)   

5 - 12 = x - 7 (combine and cancel x's from both sides)   

5 - 12 + 7 = x - 7 + 7 (add 7 to both sides)   

0 = x (add numbers together on both sides)       

so in order for the equation to be true, x must be 0.   

trying x = -0.5   

5 + x - 12 = 2x - 7 (original equation)   

5 + -0.5 - 12 = 2(-0.5) - 7 (plug in value of x)   

5 + -0.5 - 12 = -1 - 7 (did multiplication)   

-7.5 = -8 (did addition on both sides)       

since -7.5 is obviously not equal to -8, the value of -0.5 for x is wrong.   

trying x = 0   

5 + x - 12 = 2x - 7 (original equation)   

5 + 0 - 12 = 2(0) - 7 (plug in value of x)   

5 + 0 - 12 = 0 - 7 (did multiplication)   

-7 = -7 (did addition on both sides)       

since -7 equals -7, that demonstrates that the value of 0 for x is correct.   

trying x = 1   

5 + x - 12 = 2x - 7 (original equation)   

5 + 1 - 12 = 2(1) - 7 (plug in value of x)   

5 + 1 - 12 = 2 - 7 (did multiplication)   

-6 = -5 (did addition on both sides)       

since -6 is obviously not equal to -5, the value of 1 for x is wrong.