VARIATIONS B1

 

x is directly proportional to y. x=32 while y=16. Find y when x is 720.

 

Solution

 

x ⍺ y

x = ky   [ We omit ⍺ by writing it as =k ]

 

32 = k x 16

 

32 = 16k    [dividing by 16 both sides]

16    16

 

k = 2

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

 

Now; k = 2, y= ? x = 720.

 

x = ky

 

720 = 2 x y

 

720 = 2y

 2       2

 

y = 360.

 

TRY THIS…………….

 

x is directly proportional to y. x=40 while y=4. Find y when x is 430.