Question

4. I. The value of y varies directly with x. If x = 12 when y = 9, what is the equation that represents this direct variation? y= 3 1 ​ x ⊝ y= 4 3 ​ x ⊝ y= 3 4 ​ x ⊝ y=3x ⊝ CLEAR ALL

Answer 1

y =
`(3)/(4)` x

Explanation:

given y varies directly with x , then the equation relating them is

y = kx ← k is the constant of variation

to find k , substitute x = 12 , y = 9 into the equation

9 = 12k ( divide both sides by 12 )

`(9)/(12)` =
`(12)/(12)` k , that is

`(3)/(4)` = k

y =
`(3)/(4)` x ← equation of variation