Question

Find the 2 numbers if one of them exceeds other by 9 and their sum is 81

Answer 1

$$\begin{gathered} \mathrm{Let}\mathrm{the}\mathrm{first}\mathrm{number}=\mathrm{x} \\ \mathrm{then}\mathrm{the}\mathrm{second}\mathrm{number}=\mathrm{x}+9 \\ \mathrm{Now},\mathrm{according}\mathrm{to}\mathrm{question}: \\ \mathrm{x}+\mathrm{x}+9=81 \\ \Rightarrow 2\mathrm{x}+9=81 \\ \Rightarrow 2\mathrm{x}=81-9 \\ \Rightarrow 2\mathrm{x}=72 \\ \Rightarrow \mathrm{x}=\frac{72}{2}=36 \\ \mathrm{So},\mathrm{first}\mathrm{number}=36 \\ \mathrm{second}\mathrm{number}=36+9=45 \end{gathered}$$