VARIATION 5

x is inversely proportional to y. x=18 while y=5. Find y when x is 12.

Solution

x ⍺ k

      y

x = k

      y

18 = k

        5

k = 18 x 5

k = 90

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

k = 90, y= ?, x = 12.

x = k

      y

12 = 90

         y

y x 12 = 90  x  y   (multiply by y on both sides)

                y

12y = 90

12      12

y = 7.5  .

TRY THIS…………….

x is inversely proportional to y. x=24 while y=4. Find y when x is 8.