VARIATION 1

x is inversely proportional to y. x=30 while y=5. Find y when x is 15.

Solution

x ⍺ k

      y

x = k

      y

30 = k

        5

k = 30 x 5

k = 150

,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

k = 150, y= ?, x = 15.

x = k

      y

15 = 150

         y

y x 15 = 150  x  y   (multiply by y on both sides)

                y

15y = 150 ¹⁰        dividing by 15 both sides

15      15

Hence y = 10  .

TRY THIS…………….

x is inversely proportional to y. x=80 while y=4. Find y when x is 40.