Question

Variable y varies directly with variable x. If x = 12, then y = 3. What is the value of y

when x = 8?

Answer 1

y = 2

Explanation:

To find the value of y when x = 8 we must first find the relationship between the two variables.

The statement

y varies directly with variable x is written as

y = kx

where k is the constant of proportionality

when

x = 12

y = 3

Substitute the values into the above formula and solve for k

That's

3 = 12k

Divide both sides by 12

`k = (1)/(4)`

So the formula for the variation is

`y = (1)/(4) x`

when

x = 8

`y = (1)/(4) * 8`

we have the final answer as

y = 2

Hope this helps you