Question

y varies directly as x,and y =4.5 and x=0.5. A)write an equation that relates x and y. B)Find y when x =1.2. C)Find x when y=7.2

Answer 1

A. You get the equation $y(x)=\frac{4.5}{0.5} \cdot x = 9 \cdot x$
B. For x = 1.2, you get $y = 9 \cdot 1.2 = 10.8$
C. For y = 7.2, you get $x = \frac{y}{9} = \frac{7.2}{9} = 0.8$