-7(-3x3 + 6x2 -4)

To simplify the expression \(-7(-3x^3 + 6x^2 - 4)\), you need to distribute \(-7\) to each term inside the parentheses:

1. Distribute \(-7\) to \(-3x^3\): \[ -7 \cdot -3x^3 = 21x^3 \]

2. Distribute \(-7\) to \(6x^2\): \[ -7 \cdot 6x^2 = -42x^2 \]

3. Distribute \(-7\) to \(-4\): \[ -7 \cdot -4 = 28 \]

Now, combine the results: \[ 21x^3 - 42x^2 + 28 \]

So, the simplified expression is: \[ 21x^3 - 42x^2 + 28 \]