Forming equations using proportion by Boxed Rockets

Form Equations to Represent the Following

Question 1:

y is inversely proportional to x, when x = 8, y = 13

y = \frac{104}{x}

Question 2:

y is directly proportional to x, when x = 8, y = 120

y = 15 x

Question 3:

y is directly proportional to x, when x = 6, y = 54

y = 9 x

Question 4:

y is directly proportional to x, when x = 7, y = 70

y = 10 x