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

Explanation

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

### Step 1: Identify the longest carbon chain
The first step in naming any organic compound is to identify the longest continuous chain of carbon atoms. In this case, the longest chain consists of 9 carbon atoms.

### Step 2: Number the carbon chain
Next, we need to number the carbon chain. We can start numbering from either end since the compound is symmetrical. However, we will start from the left side for clarity. The numbering will be as follows:
1. C1
...