1. **State the problem:** Solve the equation $$(3x - 2)^{\frac{3}{2}} + 7 = 15$$ for $x$.
2. **Isolate the power term:** Subtract 7 from both sides:
$$ (3x - 2)^{\frac{3}{2}} = 15 - 7 $$
$$ (3x - 2)^{\frac{3}{2}} = 8 $$
3. **Rewrite the equation:** Recall that $a^{\frac{3}{2}} = (a^{\frac{1}{2}})^3 = (\sqrt{a})^3$.
4. **Take the cube root of both sides:**
$$ \sqrt{3x - 2} = \sqrt[3]{8} $$
$$ \sqrt{3x - 2} = 2 $$
5. **Square both sides to remove the square root:**
$$ (\sqrt{3x - 2})^2 = 2^2 $$
$$ 3x - 2 = 4 $$
6. **Solve for $x$:**
$$ 3x = 4 + 2 $$
$$ 3x = 6 $$
$$ x = \frac{6}{3} $$
$$ x = 2 $$
7. **Check for extraneous solutions:** Substitute $x=2$ back into the original equation:
$$ (3(2) - 2)^{\frac{3}{2}} + 7 = (6 - 2)^{\frac{3}{2}} + 7 = 4^{\frac{3}{2}} + 7 $$
$$ 4^{\frac{3}{2}} = (\sqrt{4})^3 = 2^3 = 8 $$
$$ 8 + 7 = 15 $$ which is true.
**Final answer:** $x = 2$
Solve Power Equation A0423C
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