Question

16. The value of y varies directly with x. Ifx = 10, then y = 2. What is the value of xwhen y = 7?

Answer 1

SOLUTIONS

The value of y varies directly with x. If

x = 10, then y = 2. What is the value of x

when y = 7?

Explanation:

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

`\begin{gathered} y\text{ }\alpha\text{ }x \\ y=kx \end{gathered}`

y = kx ← k is the constant of variation

to find k use the given condition y = 2 when x = 10

`\begin{gathered} k=(y)/(x)=(2)/(10)=(1)/(5) \\ y=(x)/(5) \end{gathered}`

The equation of variation

`y=(x)/(5)`

when y = 7, then, find the value of x

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