Question

The variables y and x have a proportional relationship, and y = 5 when x = 4.

What is the value of x when y = 8?



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x =

Answer 1

In a proportional relationship, we can express the relationship as:

\[
\frac{y_1}{x_1} = \frac{y_2}{x_2}
\]

From the problem, we know that when \( y = 5 \), \( x = 4 \). Therefore, we have:

\[
\frac{5}{4} = \frac{8}{x}
\]

Now we can set up the equation and cross-multiply to solve for \( x \):

\[
5x = 8 \cdot 4
\]

Calculating the right-hand side:

\[
5x = 32
\]

Now, divide both sides by 5 to isolate \( x \):

\[
x = \frac{32}{5} = 6.4
\]

Thus, the value of \( x \) when \( y = 8 \) is:

\[
x = 6.4
\]