Write the systematic IUPAC names of the following compounds:
`CH_3 - overset(CN)overset(| ) CH -CH_2 - underset(CH_3) underset(|) overset(CH_3) overset(|) C- overset(C_2 H_5)overset(|)(CH ) - CH_2 Cl`

Explanation

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

### Step 1: Identify the Functional Group
The compound contains a cyanide group (–CN), which is the main functional group. In IUPAC nomenclature, the suffix for a nitrile is “nitrile”.

**Hint:** Look for the functional group that has the highest priority in naming.

### Step 2: Determine the Longest Carbon Chain
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