The value of [tex]$y$[/tex] varies inversely with [tex]x[/tex], and [tex]$y = 7$[/tex] when [tex][tex]$x = 9$[/tex][/tex].

What is [tex]$y$[/tex] when [tex]$x = 3$[/tex]?

Remember: [tex]$y = \frac{k}{x}$[/tex]

[tex]\[ y = \ ? \][/tex]



Answer :

Let's solve the problem step-by-step.

Given:
- The value of [tex]\( y \)[/tex] varies inversely with [tex]\( x \)[/tex].
- When [tex]\( x = 9 \)[/tex], [tex]\( y = 7 \)[/tex].

We know that for inverse variation, the product [tex]\( k \)[/tex] of [tex]\( x \)[/tex] and [tex]\( y \)[/tex] remains constant:
[tex]\[ k = x \cdot y \][/tex]

First, we will calculate the constant [tex]\( k \)[/tex] using the given values of [tex]\( x \)[/tex] and [tex]\( y \)[/tex]:
[tex]\[ k = 9 \cdot 7 = 63 \][/tex]

Now that we have the constant [tex]\( k = 63 \)[/tex], we use it to find the new value of [tex]\( y \)[/tex] when [tex]\( x = 3 \)[/tex]:
[tex]\[ y = \frac{k}{x} \][/tex]

Substitute [tex]\( k = 63 \)[/tex] and [tex]\( x = 3 \)[/tex] into the equation:
[tex]\[ y = \frac{63}{3} = 21 \][/tex]

So, the value of [tex]\( y \)[/tex] when [tex]\( x = 3 \)[/tex] is:
[tex]\[ y = 21 \][/tex]