Forming equations using proportion by Boxed Rockets

Form Equations to Represent the Following

Question 1:

y is directly proportional to x, when x = 6, y = 24

y = 4 x

Question 2:

y is directly proportional to x, when x = 1, y = 10

y = 10 x

Question 3:

y is inversely proportional to x, when x = 9, y = 11

y = \frac{99}{x}

Question 4:

y is inversely proportional to x, when x = 9, y = 7

y = \frac{63}{x}