Is CH₃CH(CH₂CH₃)₂ the same as CH₃CH(CH₃CH₂)₂
In chemistry, as in any &quot;language&quot;, there is what must be said to be correct: it is the 1st way your molecule is written.
Your second way of writing it is not wrong but it does not correspond to the globally institutionalized standard. The goal for any language is to be understood no matter where you are.
The conventions indicate that it should be written $\ce{CH3-CH-(CH2-CH3)2}$ which does not induce any ambiguity