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zaharov [31]
3 years ago
10

Y and x have a proportional relationship, and y = 15 when x = 3. What is the value of x when y = 4?

Mathematics
1 answer:
Alex73 [517]3 years ago
4 0
X would be 20 because is like sipmle multipulcation by 5 Ex. 3x5=15 like 4x5=20
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If 3x-13=8, find the value of -4?
sukhopar [10]
If you're looking for x then it's 7. The value of -4 is -4.
7 0
2 years ago
Given the function f(x)=3x+5a / x^2-a^2 find the value of a for which f'(12) = 0
maria [59]
The function, as presented here, is ambiguous in terms of what's being deivded by what.  For the sake of example, I will assume that you meant

           3x+5a
<span> f(x)= ------------
</span>          x^2-a^2

You are saying that the derivative of this function is 0 when x=12.  Let's differentiate f(x) with respect to x and then let x = 12:

             (x^2-a^2)(3) -(3x+5a)(2x)
f '(x) = ------------------------------------- = 0 when x = 12
                [x^2-a^2]^2

(144-a^2)(3) - (36+5a)(24)
------------------------------------  =  0
               [   ]^2

Simplifying,

(144-a^2) - 8(36+5a) = 0

144 - a^2 - 288 - 40a = 0

This can be rewritten as a quadratic in standard form:

-a^2 - 40a - 144 = 0, or a^2 + 40a + 144 = 0.

Solve for a by completing the square:

a^2 + 40a + 20^2 - 20^2 + 144 = 0
        (a+20)^2    = 400 - 144 = 156

        Then a+20 = sqrt[6(26)] = sqrt[6(2)(13)] = 4(3)(13)= 2sqrt(39)

         Finally, a = -20 plus or minus 2sqrt(39)

You must check both answers by subst. into the original equation.  Only if the result(s) is(are) true is your solution (value of a) correct.
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Answer:

answer is B

it is less than Zx for set B

Step-by-step explanation:

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If you could show a photo I could answer the question
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Given g(x) = –2 – 1, solve for a when g(x) = 3.<br> Answer:<br> Submit Answer
sergejj [24]

Answer:

oopStep-by-step explanation:

8 0
2 years ago
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