Answer: 3) k = 22.5; xy = 22.5
Step-by-step explanation:
If two variables are inversely proportional, it means that an increase in the value of one variable would cause a corresponding decrease in the other variable. Also, a decrease in the value of one variable would cause a corresponding increase in the other variable.
Given that y varies directly with x, if we introduce a constant of proportionality, k, the expression becomes
y = k/x
If y = 2.5 when x = 9, then
2.5 = k/9
k = 9 × 2.5 = 22.5
Therefore, an equation for the inverse variation is
y = 22.5/x
xy = 22.5
