Question

(1) If y varies directly as x, and x = 3 and y = 9, solve for k

Write an equation that relates x & y


(2) If y varies inversely as x, and x = 3 and y = 12, Solve for k Write an equation that relates x & yIf y varies directly as x, and x = 3 and y = 9, solve for k

Write an equation that relates x & y


(3). If y varies inversely as x, and x = 3 and y = 12, Solve for k

Write an equation that relates x & y

Answer 1

`(1)y=(1)/(3)x\\\\(2)y=(36)/(x)`

Explanation:

(1)

`y \propto x\\y=kx\\$When x=3 and y=9\\9=3k; Therefore: $k=(1)/(3) \\$The equation that relates x and y is:$\\y=(1)/(3)x`

(2)

`y \propto (1)/(x)\\y = (k)/(x)\\$When x=3 and y=12$\\12 = (k)/(3); $Therefore: $k=3*12=36 \\$The equation that relates x and y is:$\\y=(36)/(x)`

Question 3 is a repetition of Question 2.