Question

whatttttttt! Find an equation of variation where y varies directly as x. One pair of values is y = 80 when x = 40.

Answer 1

y is directly proportional to x
y = 80
x = 40
So as y increases even x increases and vice versa!
So
y = 2x
Got it? :)

Answer 2

it says y = kx

Answer 3

@AkashdeepDeb

Answer 4

k is a replacement for a CONSTANT!!
In this case they tell us to find an EQUATION!
So
y = 2x
x = 40, y=80
So we can also say that when x=1 then y = 2
Understood? :)