VARIATIONS A1

x is directly proportional to y. x=12 while y=4. Find y when x is 30.

Solution

x ⍺ y

x = ky

12 = k x 4

12 = 4k

4      4

k = 3

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

k = 3, y= ? x = 30.

30 = 3 x y

30 = 3y

3      3

y = 10.

TRY THIS…………….

x is directly proportional to y. x=20 while y=4. Find y when x is 30.