[tex]\begin{gathered} \frac{20}{72}=\frac{x}{360} \\ \text{You simplify the left hand side of the equation},\text{ i.e divide by 4} \\ \frac{5}{18}=\frac{x}{360} \\ \text{You cross multiply and you now have} \\ 5\times360=18x \\ \text{Divide both sides by 18 which is the coefficient of x} \\ 5\times20=x \\ 100=x \end{gathered}[/tex]
The value of x = 100