if y veries directly as x and y=12 when x=3, find y when x=7
Answer (1)
[tex]\text{Given: } y \text{ varies directly as } x \quad \Rightarrow \quad y = kx[/tex]1. Find the constant of variation k using y=12 when x=3:[tex]12 = k(3) \quad \Rightarrow \quad k = \frac{12}{3} = 4[/tex]2. Use k to find y when x=7:[tex]y = kx = 4 \cdot 7 = 28[/tex][tex]\boxed{y = 28}[/tex]
