Question

The value of y varies directly with x. If x = 10, then y = 2. What is the value of x when y = 7?

Answer 1

Step-by-step explanation:

Concept:

The value of y varies directly with x can be represented below as

`\begin{gathered} y\propto x \\ y=kx \end{gathered}`

Step 1:

Calculate the value of k by putting x=10 and y=2

`\begin{gathered} y=kx \\ 2=10k \\ divide\text{ both sides by 10} \\ (10k)/(10)=(2)/(10) \\ k=(1)/(5) \end{gathered}`

Step 2:

Form the equation connecting y and x below as

`\begin{gathered} y=kx \\ y=(1)/(5)x \end{gathered}`

Step 3:

Fin the value of x when y=7

`\begin{gathered} y=(1)/(5)x \\ 7=(x)/(5) \\ x=7*5 \\ x=35 \end{gathered}`

Hence,

The final answer is

`x=35`