Write and solve the equation for the direct variation y varies directly with x if y=5 when x=55 . Then find the value of y when x=22 .

1 answer

In direct variation, we can express the relationship between \( y \) and \( x \) as follows:

\[ y = kx \]

where \( k \) is a constant.

Given that \( y = 5 \) when \( x = 55 \), we can substitute these values into the equation to find \( k \):

\[ 5 = k(55) \]

To solve for \( k \), we divide both sides by 55:

\[ k = \frac{5}{55} \]

Simplifying this gives:

\[ k = \frac{1}{11} \]

Now that we have \( k \), the equation relating \( y \) and \( x \) is:

\[ y = \frac{1}{11}x \]

Next, we need to find the value of \( y \) when \( x = 22 \). We substitute \( x = 22 \) into the equation:

\[ y = \frac{1}{11}(22) \]

Calculating this gives:

\[ y = \frac{22}{11} = 2 \]

Thus, the value of \( y \) when \( x = 22 \) is:

\[ \boxed{2} \]