Answer:
The equation which correctly relates x and y is y = 4x
Explanation:
The equation of the direct variation is y = k x, where
- k is the constant of variation
- To find the value of k, use the initial values of x and y
∵ The variables x and y vary directly
→ Use the form of the equation above
∴ y = k x
∵ When x = 13, y = 52
→ That means the initial values of x and y are 13 and 52
∴ x = 13 and y = 52
→ Substitute them in the equation above to find k
∵ 52 = k (13)
∴ 52 = 13k
→ Divide both sides by 13
∴ 4 = k
∴ The value of k is 4
→ Substitute it in the equation
∴ y = 4x
∴ The equation which correctly relates x and y is y = 4x