1. We are given the inequality $\left(\frac{2}{3}\right)^{x-2} > \frac{9}{4}$. We want to find the values of $x$ that satisfy this.
2. Recall that $\left(\frac{2}{3}\right)^{x-2} = \frac{2^{x-2}}{3^{x-2}}$ and $\frac{9}{4} = \left(\frac{3}{2}\right)^2$. Since $\frac{2}{3} < 1$, the function $\left(\frac{2}{3}\right)^t$ is decreasing in $t$.
3. Rewrite the inequality as:
$$\left(\frac{2}{3}\right)^{x-2} > \left(\frac{3}{2}\right)^2$$
4. Because $\left(\frac{2}{3}\right)^{x-2} = \left(\frac{3}{2}\right)^{-(x-2)}$, the inequality becomes:
$$\left(\frac{3}{2}\right)^{-(x-2)} > \left(\frac{3}{2}\right)^2$$
5. Since $\frac{3}{2} > 1$, the function $\left(\frac{3}{2}\right)^t$ is increasing, so the inequality
$$-(x-2) > 2$$
must hold.
6. Simplify:
$$-x + 2 > 2$$
$$-x > 0$$
$$\cancel{-}x > \cancel{0}$$
Multiply both sides by $-1$ and reverse inequality:
$$x < 0$$
7. Final solution for the first inequality is:
$$\boxed{x < 0}$$
Exponential Inequality A7B113
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