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PLS HELP!! 15 points

Consider the following function: f(x) = 3x-1 / x+4
a) At which value of x will the function not have an answer? Explain.
b) If g(x) is a vertical shift of 4 units of f(x), write the function g(x). How does the graph of g(x) compare to the graph of f(x)? Explain the function you wrote.
c) What is the value of x when g(x) = 8? Show your work.
thank u :)

User Dgrant
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1 Answer

4 votes

we are given


f(x)=(3x-1)/(x+4)

(a)

We know that when denominator of any function is 0

then function will become undefined

so, denominator=0 will make function no solution

so, we set denominator =0

and then we solve for x


x+4=0


x=-4............Answer

(b)

Vertical shift:

Suppose, we want to shift y=f(x) function vertically by 'c' units

we add 'c' top y-value

so, new function will become


y=f(x)+c

now, we have

If g(x) is a vertical shift of 4 units of f(x)

so, we can write our function as


g(x)=f(x)+4

we can plug f(x)


g(x)=(3x-1)/(x+4)+4

Comparison:

So, graph of f(x) is moved upside by 4 units to get graph of g(x)


(c)

We can set g(x)=8

and then we can solve for x


g(x)=(3x-1)/(x+4)+4=8

Multiply both sides by x+4


(3x-1)/(x+4)\left(x+4\right)+4\left(x+4\right)=8\left(x+4\right)


3x-1+4\left(x+4\right)=8\left(x+4\right)


7x+15=8x+32


7x=8x+17


-x=17


x=-17..............Answer

User CactusCake
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