Question

Find the constant of variation for the relation and use it to write an equation for the statement. Then solve the equation.

Answer 1

Answer: option c

Step-by-step explanation:

Based on the information given, you can write the following expression:

$y=\frac{k}{x^2}$

Where k is the the constant of variation

If y=7/4 when x=1, then you can substitute these values into the expression and solve for k:

$\frac{7}{4}=\frac{k}{1^2}\\k=1*\frac{7}{4}\\k=\frac{7}{4}$

Substitute k into the expression. Then the equation is:

$y=\frac{7}{4x^{2}}$

Substitute x=3   into the equation. Then, y is:

$y=\frac{7}{4(3)^{2}}=\frac{7}{36}}$

Answer 2

Answer:

Choice C is the answer.

Step-by-step explanation:

We have given that

If y varies inversely as the square of x

y ∝ 1/x²

y  = k/x²                 ��      eq(1)

where k is constant of variation.

As given that y = 7/4 when x = 1

7/4 = k/(1)²

7/4 = k/(1)

7/4 = k

Putting the value of k in eq(1), we have

y = 7/4x²

Now, we have to find the value of y when x = 3

y = 7/4(3)²

y = 7/4(9)

y = 7/36

Choice C is the answer.