Problem
Suppose that \( y \) varies inversely with \( x \), and \( y=10 \) when \( x=-2 \). (a) Write an inverse variation equation that relates \( x \) and \( y \). Equation: (b) Find \( y \) when \( x=-25 \). \[ y= \]
Solution
Step 1 ：\(k=x\cdot y\)
Step 2 ：k=-2 \cdot 10 = -20
Step 3 ：\(y=-\frac{20}{-25}=\frac{4}{5}\)
