[tex]\bf 1365=x+(1\cdot x\cdot 5\%)\\\\
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whatever\%~of~anything\implies \cfrac{whatever}{100}\cdot anything\\\\
-------------------------------\\\\[/tex]
[tex]\bf 1365=x+\left( 1\cdot x\cdot \frac{5}{100} \right)\implies 1365=x+\left(x\cdot \frac{5}{100} \right)
\\\\\\
1365=x+\left(\frac{x\cdot 5}{100} \right)\implies 1365=x+\cfrac{5x}{100}\impliedby \textit{using LCD of \underline{100}}
\\\\\\
1365=\cfrac{100x+5x}{100}\implies 1365\cdot 100=100x+5x
\\\\\\
136500=105x
\implies
\cfrac{136500}{105}=x\implies 1300=x[/tex]