(3a*3a-4)(1-a*a)+8

To simplify the expression \( (3a \cdot 3a - 4)(1 - a^2) + 8 \), let's break it down step by step.

1. Simplify \( 3a \cdot 3a \): \[ 3a \cdot 3a = 9a^2 \] So, the expression becomes: \[ (9a^2 - 4)(1 - a^2) + 8 \]

2. Now, expand \( (9a^2 - 4)(1 - a^2) \): \[ (9a^2 - 4)(1 - a^2) = 9a^2 \cdot 1 + 9a^2 \cdot (-a^2) - 4 \cdot 1 - 4 \cdot (-a^2) \] Simplifying this: \[ = 9a^2 - 9a^4 - 4 + 4a^2 \] Combine like terms: \[ = (9a^2 + 4a^2) - 9a^4 - 4 = 13a^2 - 9a^4 - 4 \]

3. Now include the \( + 8 \): \[ 13a^2 - 9a^4 - 4 + 8 = 13a^2 - 9a^4 + 4 \]

4. Rewrite in standard form: \[ -9a^4 + 13a^2 + 4 \]

So, the simplified expression is: \[ -9a^4 + 13a^2 + 4 \]