1. **State the problem:** We are given five expressions:
$$A = x(x+2) + 2x(x+1)$$
$$B = 8(x+5) - 2(7x+20)$$
$$C = (x-4)x(2x-3) + x - 1$$
$$D = (x+4)x(x-5) - (x+3)$$
$$E = (5x-3)x(x+2) + x(x+3)$$
We need to simplify each expression.
2. **Recall the distributive property:**
$$a(b+c) = ab + ac$$
We will apply this to expand and then combine like terms.
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3. **Simplify A:**
$$A = x(x+2) + 2x(x+1) = x^2 + 2x + 2x^2 + 2x = (x^2 + 2x^2) + (2x + 2x) = 3x^2 + 4x$$
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4. **Simplify B:**
$$B = 8(x+5) - 2(7x+20) = 8x + 40 - 14x - 40 = (8x - 14x) + (40 - 40) = -6x + 0 = -6x$$
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5. **Simplify C:**
First expand $(x-4)x(2x-3)$:
$$ (x-4)x(2x-3) = (x-4)(2x^2 - 3x) = x(2x^2 - 3x) - 4(2x^2 - 3x) = 2x^3 - 3x^2 - 8x^2 + 12x = 2x^3 - 11x^2 + 12x$$
Now add $x - 1$:
$$C = 2x^3 - 11x^2 + 12x + x - 1 = 2x^3 - 11x^2 + 13x - 1$$
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6. **Simplify D:**
First expand $(x+4)x(x-5)$:
$$ (x+4)x(x-5) = (x+4)(x^2 - 5x) = x(x^2 - 5x) + 4(x^2 - 5x) = x^3 - 5x^2 + 4x^2 - 20x = x^3 - x^2 - 20x$$
Now subtract $(x+3)$:
$$D = x^3 - x^2 - 20x - x - 3 = x^3 - x^2 - 21x - 3$$
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7. **Simplify E:**
First expand $(5x-3)x(x+2)$:
$$ (5x-3)x(x+2) = (5x-3)(x^2 + 2x) = 5x(x^2 + 2x) - 3(x^2 + 2x) = 5x^3 + 10x^2 - 3x^2 - 6x = 5x^3 + 7x^2 - 6x$$
Now add $x(x+3) = x^2 + 3x$:
$$E = 5x^3 + 7x^2 - 6x + x^2 + 3x = 5x^3 + 8x^2 - 3x$$
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**Final answers:**
$$A = 3x^2 + 4x$$
$$B = -6x$$
$$C = 2x^3 - 11x^2 + 13x - 1$$
$$D = x^3 - x^2 - 21x - 3$$
$$E = 5x^3 + 8x^2 - 3x$$
Simplify Expressions 3Dac81
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