(с-3)(с+4)-с²

To simplify the expression \((c-3)(c+4) - c^2\), follow these steps: 1. First, expand the expression \((c-3)(c+4)\): \[ (c-3)(c+4) = c \cdot c + 4c - 3c - 12 = c^2 + c - 12 \] 2. Now, substitute this back into the original expression: \[ (c^2 + c - 12) - c^2 \] 3. Now, simplify the expression by subtracting \(c^2\): \[ c^2 + c - 12 - c^2 = c - 12 \] So, the simplified expression is: \[ c - 12 \]