Question

x | y
2 | 5
4 | 10
8 | 20
○ not direct variation
○ direct variation
equation:
□

Explanation:

Step1: Check direct variation ratio

For each pair, calculate $\frac{y}{x}$:
$\frac{5}{2}=2.5$, $\frac{10}{4}=2.5$, $\frac{20}{8}=2.5$

Step2: Define direct variation form

Direct variation follows $y=kx$, where $k$ is the constant ratio.
Substitute $k=2.5=\frac{5}{2}$ into the form:
$y=\frac{5}{2}x$

Answer:

Direct variation
Equation: $y=\frac{5}{2}x$