Question

Solve the proportion for x

Answer 1

$\begin{gathered}\\ \sf\longmapsto \frac{45}{40}=\frac{9}{x}\end{gathered}$

$\begin{gathered}\\ \sf\longmapsto \cancel{\dfrac{45}{40}}=\frac{9}{x}\end{gathered}$

$\begin{gathered}\\ \sf\longmapsto \frac{9}{8}=\frac{9}{x}\end{gathered}$

✎When the denominators are the same, set the numerators equal

$\begin{gathered}\\ \sf\longmapsto 9=x\end{gathered}$

✎Swap the sides of the equation

$\begin{gathered}\\ \sf\longmapsto x=9\end{gathered}$

Answer 2

Solution:

$\frac{45}{40} = \frac{9}{x} \\ = > \frac{40}{45} = \frac{x}{9} \\ = > x = \frac{40}{45} \times 9 \\ = > x = \frac{40}{5} \\ = > x = 8$

Answer:

x = 8