1. Solve the inequality $$\frac{1}{x+2} \leq \frac{2}{3x+1}$$ algebraically.
2. First, bring all terms to one side to form a single inequality:
$$\frac{1}{x+2} - \frac{2}{3x+1} \leq 0$$
3. Find a common denominator and combine the fractions:
$$\frac{(3x+1) - 2(x+2)}{(x+2)(3x+1)} \leq 0$$
4. Simplify the numerator:
$$3x + 1 - 2x - 4 = x - 3$$
So the inequality becomes:
$$\frac{x - 3}{(x+2)(3x+1)} \leq 0$$
5. Identify critical points where numerator or denominator is zero:
- Numerator zero at $x=3$
- Denominator zero at $x=-2$ and $x=-\frac{1}{3}$
6. These points divide the number line into intervals:
$$(-\infty, -2), (-2, -\frac{1}{3}), (-\frac{1}{3}, 3), (3, \infty)$$
7. Test each interval to determine the sign of the expression:
- For $x < -2$, pick $x=-3$:
$$\frac{-3 - 3}{(-3+2)(3(-3)+1)} = \frac{-6}{(-1)(-8)} = \frac{-6}{8} < 0$$
- For $-2 < x < -\frac{1}{3}$, pick $x=-1$:
$$\frac{-1 - 3}{(-1+2)(3(-1)+1)} = \frac{-4}{(1)(-2)} = \frac{-4}{-2} = 2 > 0$$
- For $-\frac{1}{3} < x < 3$, pick $x=0$:
$$\frac{0 - 3}{(0+2)(3(0)+1)} = \frac{-3}{(2)(1)} = -\frac{3}{2} < 0$$
- For $x > 3$, pick $x=4$:
$$\frac{4 - 3}{(4+2)(3(4)+1)} = \frac{1}{(6)(13)} > 0$$
8. The inequality requires the expression to be less than or equal to zero, so include intervals where expression is negative or zero.
9. Check if critical points are included:
- At $x=3$, numerator zero, expression equals zero, include $x=3$.
- At $x=-2$ or $x=-\frac{1}{3}$, denominator zero, expression undefined, exclude these points.
10. Final solution:
$$(-\infty, -2) \cup \left(-\frac{1}{3}, 3\right]$$
Inequality Rational Bc91Ef
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