Evaluate :
`2a^(3)` when a=-2

Answer

To evaluate the expression \( 2a^3 \) when \( a = -2 \), follow these steps:

### Step 1: Substitute the value of \( a \)
We start with the expression:
\[ 2a^3 \]
Now, substitute \( a = -2 \):
\[ 2(-2)^3 \]

### Step 2: Calculate \( (-2)^3 \)
Next, we need to calculate \( (-2)^3 \). This means multiplying \(-2\) by itself three times:
\[ (-2) \times (-2) \times (-2) \]
Calculating this step-by-step:
1. First, multiply the first two \(-2\):
\[ (-2) \times (-2) = 4 \]
2. Now, multiply the result by the third \(-2\):
\[ 4 \times (-2) = -8 \]

So, \( (-2)^3 = -8 \).

### Step 3: Multiply by 2
Now, substitute \( (-2)^3 \) back into the expression:
\[ 2 \times (-8) \]
Calculating this gives:
\[ 2 \times (-8) = -16 \]

### Final Answer
Thus, the value of \( 2a^3 \) when \( a = -2 \) is:
\[ \boxed{-16} \]