Forming equations using proportion by Boxed Rockets

Form Equations to Represent the Following

Question 1:

y is directly proportional to x, when x = 10, y = 60

y = 6 x

Question 2:

y is inversely proportional to x, when x = 7, y = 4

y = \frac{28}{x}

Question 3:

y is directly proportional to x, when x = 12, y = 108

y = 9 x

Question 4:

y is directly proportional to x, when x = 8, y = 48

y = 6 x