1. **Expand and simplify** the expression $(x + 5)(x + 4)(x - 3)$ to find constants $A$, $B$, $C$, and $D$.
Start by expanding two brackets first:
$$(x + 5)(x + 4) = x^2 + 4x + 5x + 20 = x^2 + 9x + 20$$
Now multiply this result by $(x - 3)$:
$$ (x^2 + 9x + 20)(x - 3) = x^2(x - 3) + 9x(x - 3) + 20(x - 3) $$
$$ = x^3 - 3x^2 + 9x^2 - 27x + 20x - 60 $$
Combine like terms:
$$ x^3 + ( -3x^2 + 9x^2 ) + ( -27x + 20x ) - 60 = x^3 + 6x^2 - 7x - 60 $$
So,
$$ A = 1, B = 6, C = -7, D = -60 $$
2. **Solve the simultaneous equations:**
$$ 2x - 8y = -10 $$
$$ -10x - ? = ? $$
The second equation is incomplete in the prompt. Assuming it is $-10x - y = ?$, please provide the full second equation to solve.
3. **Solve the linear inequality:**
$$ 2x + 10 \geq -10x - 7 $$
Add $10x$ to both sides:
$$ 2x + 10x + 10 \geq -7 $$
$$ 12x + 10 \geq -7 $$
Subtract 10 from both sides:
$$ 12x \geq -17 $$
Divide both sides by 12:
$$ x \geq \frac{-17}{12} $$
This is the solution in lowest terms.
**Final answers:**
- For expansion: $A=1$, $B=6$, $C=-7$, $D=-60$
- For inequality: $x \geq \frac{-17}{12}$
Please provide the full second equation for question 7 to solve it completely.
Expand Simultaneous Inequality
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