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soldi70 [24.7K]
3 years ago
7

If x + y = 12 and xy = -5, calculate the value of 1/x + 1/y.​

Mathematics
1 answer:
Paul [167]3 years ago
8 0

\dfrac{1}{x}+\dfrac{1}{y}=\dfrac{y}{xy}+\dfrac{x}{xy}=\dfrac{x+y}{xy}=\dfrac{12}{-5}=-\dfrac{12}{5}=-2,4

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Which graph represents the function of f(x) 9x^2 + 9x - 18 / 3x + 6
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Answer:

The graph in the attached figure

Step-by-step explanation:

we have

f(x)=\frac{9x^{2}+9x-18}{3x+6}

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so

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Simplify the expression

Using a graphing tool

The roots of the quadratic equation in the numerator are

x=-2 and x=1

so

9x^{2}+9x-18=9(x+2)(x-1)

Simplify the denominator

3x+6=3(x+2)

substitute in the original expression

f(x)=\frac{9(x+2)(x-1)}{3(x+2)}

Simplify

f(x)=3(x-1)

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Is the equation of a line

The y-intercept is the point (0,-3) (value of the function when x is equal to zero)

The x-intercept is the point (1,0) (value of x when the value of the function is equal to zero)

Graph the line, but remember that the value of  x cannot be equal to -2

The graph in the attached figure

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P(x) =x and q(x) = x-1Given:minimum x and Maximum x: -9.4 and 9.4minimum y and maximum y: -6.2 and 6.2Using the rational functio
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From the graph, we can see that we cannot draw the graph having a continous drawing. That is, imagine we take a pencil and start on one point on the graph on the left side. We can draw the whole graph on the left side, but we cannot draw the graph on the right side without lifting the pencil up. As we have to "lift the pencil up" this means that the graph is not continous

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