Forming equations using proportion by Boxed Rockets

Form Equations to Represent the Following

Question 1:

y is inversely proportional to x, when x = 2, y = 9

y = \frac{18}{x}

Question 2:

y is inversely proportional to x, when x = 1, y = 9

y = \frac{9}{x}

Question 3:

y is inversely proportional to x, when x = 8, y = 12

y = \frac{96}{x}

Question 4:

y is directly proportional to x, when x = 3, y = 42

y = 14 x