1. **Problem statement:** Find the products of the expressions:
i) $ (a - 1)(a^2 + a + 1) $
ii) $ (8 + b)(64 - 8b + b^2) $
2. **Solution for i):**
Use distributive property (FOIL for polynomials):
$$ (a - 1)(a^2 + a + 1) = a(a^2 + a + 1) - 1(a^2 + a + 1) $$
$$ = a^3 + a^2 + a - a^2 - a - 1 $$
Simplify by combining like terms:
$$ a^3 + (a^2 - a^2) + (a - a) - 1 = a^3 - 1 $$
3. **Solution for ii):**
Recognize the pattern as a product of sum and difference of cubes:
$$ (8 + b)(64 - 8b + b^2) $$
Note that $8 = 2^3$ and $64 = 4^3$ but here better to multiply directly:
Multiply each term:
$$ 8 imes 64 = 512 $$
$$ 8 imes (-8b) = -64b $$
$$ 8 imes b^2 = 8b^2 $$
$$ b imes 64 = 64b $$
$$ b imes (-8b) = -8b^2 $$
$$ b imes b^2 = b^3 $$
Sum all terms:
$$ 512 - 64b + 8b^2 + 64b - 8b^2 + b^3 $$
Combine like terms:
$$ 512 + (-64b + 64b) + (8b^2 - 8b^2) + b^3 = 512 + 0 + 0 + b^3 = b^3 + 512 $$
4. **Final answers:**
i) $a^3 - 1$
ii) $b^3 + 512$
Algebraic Products
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