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3 years ago

Y is directly proportional to x squared. if y=12 when x=2 find x when y=48

Mathematics

1 answer:

Alexxx [7]3 years ago

8 0

Answer:

x = 4

Step-by-step explanation:

y = kx²

NOTE: k is constant for proportionality

putting values for x and y

if x is 2

and y is 12

12 = k(2)²

12 = k4

12 = 4k

divide both sides by coefficient of k

12÷4 = 4k ÷ 4

k=3

substitute 3 for k

therefore when

y is 48

and k is constant 3

then x will be:

48=3x²

divide both sides by coefficient of x²

48 divide by 3 = 3x² divide by 3

16=x²

take the square root of both sides

√16 = √x²

x = 4

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Hi there! Let me know if you have questions about my answer:

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Step-by-step explanation:

To find the cost of each item, write a system of equations, one equation for what each person bought, and solve for each variable.

Define your variables.

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Create a system using the variables and information from the question.

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Now you have an expression for 'd'.

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Substitute 'r' for 11 using either Arjun's or Jessica's equation. Then, isolate 'd' to solve for the cost of one daylily.

I will use Arjun's equation.

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$5d + 7(11) = 97$ Substitute 'r' for r = 11

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