Question

if y varies directly as x, and y is 20 when x is 4, what is the constant of variation for this relation?
○ \\(\frac{1}{5}\\)
○ \\(\frac{4}{5}\\)
○ 5
○ 16

Explanation:

Step1: Recall direct variation formula

The formula for direct variation is \( y = kx \), where \( k \) is the constant of variation.

Step2: Substitute given values

We know \( y = 20 \) and \( x = 4 \). Substitute these into the formula: \( 20 = k \times 4 \).

Step3: Solve for \( k \)

Divide both sides of the equation by 4: \( k=\frac{20}{4}=5 \).

Answer:

5 (corresponding to the option "5")