(6) Which equation shown below shows a linear relationship between \( x \) and \( y \) ? (A) \( y=3 x+4 \) (B) \( y=1 / 2 x^{2}-1 \) (C) \( 2 x^{2}+y=5 \) (D) \( y=\frac{2}{x} \)

Step 1 ：\(\text{A linear relationship between } x \text{ and } y \text{ is represented by an equation of the form } y = m x + b\)

Step 2 ：\(\text{Checking each equation, only (A) fits this form: } y = 3x + 4\)

Step 3 ：\(\text{The other equations have either square terms or fractions containing } x \text{ in the denominator}\)