Exponent Equation Identity
1. Stating the problems:
We have two separate problems to solve:
**Problem 1:** Solve for $x$ in the equation $$16^{3x-2} = \left(\frac{1}{4}\right)^{5-x}$$
**Problem 2:** Verify the algebraic identity $$x^3 + y^3 = (x + y)(x^2 - xy + y^2)$$
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2. Solving Problem 1:
Step 1: Express both sides with the same base or related bases.
We know $16 = 2^4$ and $\frac{1}{4} = 4^{-1} = (2^2)^{-1} = 2^{-2}$.
Rewrite the equation as:
$$16^{3x-2} = \left(\frac{1}{4}\right)^{5-x} \implies (2^4)^{3x-2} = (2^{-2})^{5-x}$$
Step 2: Simplify powers of powers by multiplying exponents:
$$2^{4(3x-2)} = 2^{-2(5-x)}$$
Which becomes:
$$2^{12x - 8} = 2^{-10 + 2x}$$
Step 3: Since the bases are the same and nonzero, set exponents equal:
$$12x - 8 = -10 + 2x$$
Step 4: Solve for $x$:
$$12x - 2x = -10 + 8$$
$$10x = -2$$
$$x = -\frac{2}{10} = -\frac{1}{5}$$
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3. Verifying Problem 2:
Step 1: Expand the right-hand side expression:
$$ (x + y)(x^2 - xy + y^2) = x \cdot x^2 - x \cdot xy + x \cdot y^2 + y \cdot x^2 - y \cdot xy + y \cdot y^2 $$
Simplify the terms:
$$ = x^3 - x^2 y + x y^2 + x^2 y - x y^2 + y^3 $$
Step 2: Combine like terms:
Notice $- x^2 y$ and $+ x^2 y$ cancel out, also $+ x y^2$ and $- x y^2$ cancel out, leaving:
$$ x^3 + y^3 $$
Therefore, the identity is verified as:
$$ x^3 + y^3 = (x + y)(x^2 - xy + y^2) $$
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**Final answers:**
- For Problem 1: $$x = -\frac{1}{5}$$
- For Problem 2: The identity holds true as given.