Write the systematic IUPAC names of the following compounds:
`CH_3 - C-= C - underset(C_2 H_5 ) underset(|) overset(CH_3) overset(| ) C- CH_3`

Explanation

To derive the systematic IUPAC name of the given compound, we will follow these steps:

### Step 1: Identify the Longest Carbon Chain
First, we need to identify the longest continuous carbon chain in the compound. The longest chain should include the maximum number of double or triple bonds and functional groups.

**Hint:** Look for the longest sequence of carbon atoms that connects without any interruptions.

### Step 2: Number the Carbon Chain
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