Rational Equations 273950
1. Solve the equation $\frac{x}{3} + \frac{y}{4} = \frac{x}{2}$ for $y$.
Step 1: Multiply both sides by 12 (the least common multiple of 3, 4, and 2) to clear denominators:
$$12 \times \left(\frac{x}{3} + \frac{y}{4}\right) = 12 \times \frac{x}{2}$$
$$4x + 3y = 6x$$
Step 2: Rearrange to isolate $y$:
$$3y = 6x - 4x$$
$$3y = 2x$$
$$y = \frac{2x}{3}$$
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2. Solve $\frac{1}{x^2} = 16$.
Step 1: Multiply both sides by $x^2$:
$$1 = 16x^2$$
Step 2: Divide both sides by 16:
$$x^2 = \frac{1}{16}$$
Step 3: Take the square root:
$$x = \pm \frac{1}{4}$$
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3. Solve the inequality $\frac{x + 3}{x - 2} \leq 1$.
Step 1: Subtract 1 from both sides:
$$\frac{x + 3}{x - 2} - 1 \leq 0$$
Step 2: Write with common denominator:
$$\frac{x + 3 - (x - 2)}{x - 2} \leq 0$$
$$\frac{x + 3 - x + 2}{x - 2} \leq 0$$
$$\frac{5}{x - 2} \leq 0$$
Step 3: Since numerator 5 is positive, inequality depends on denominator:
$$x - 2 < 0 \implies x < 2$$
Step 4: Domain excludes $x=2$ (denominator zero), so solution is:
$$(-\infty, 2)$$
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4. Solve the inequality $\frac{3x + 1}{x - 1} > 2$.
Step 1: Subtract 2:
$$\frac{3x + 1}{x - 1} - 2 > 0$$
Step 2: Common denominator:
$$\frac{3x + 1 - 2(x - 1)}{x - 1} > 0$$
$$\frac{3x + 1 - 2x + 2}{x - 1} > 0$$
$$\frac{x + 3}{x - 1} > 0$$
Step 3: Find critical points where numerator or denominator zero:
$$x + 3 = 0 \implies x = -3$$
$$x - 1 = 0 \implies x = 1$$
Step 4: Test intervals:
- For $x < -3$, numerator negative, denominator negative, fraction positive.
- For $-3 < x < 1$, numerator positive, denominator negative, fraction negative.
- For $x > 1$, numerator positive, denominator positive, fraction positive.
Step 5: Solution where fraction $> 0$ and denominator $\neq 0$:
$$(-\infty, -3) \cup (1, \infty)$$
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5. Analyze the functions:
Function 1: $$y = \frac{2x + 4}{x + 3}$$
- Domain: All real $x$ except $x = -3$ (denominator zero).
- Vertical asymptote: $x = -3$.
- Horizontal asymptote: Degree numerator = degree denominator = 1, so divide leading coefficients:
$$y = \frac{2x}{x} = 2$$
So horizontal asymptote at $y = 2$.
- Intercepts:
- $y$-intercept: Set $x=0$:
$$y = \frac{0 + 4}{0 + 3} = \frac{4}{3}$$
- $x$-intercept: Set numerator zero:
$$2x + 4 = 0 \implies x = -2$$
Function 2: $$f(x) = \frac{4x + 1}{x^2 - 9} = \frac{4x + 1}{(x - 3)(x + 3)}$$
- Domain: All real $x$ except $x = 3$ and $x = -3$.
- Vertical asymptotes: $x = 3$ and $x = -3$.
- Horizontal asymptote: Degree numerator 1, denominator 2, so horizontal asymptote at $y=0$.
- Intercepts:
- $y$-intercept: Set $x=0$:
$$f(0) = \frac{1}{-9} = -\frac{1}{9}$$
- $x$-intercept: Set numerator zero:
$$4x + 1 = 0 \implies x = -\frac{1}{4}$$
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Summary:
- Solutions:
1. $y = \frac{2x}{3}$
2. $x = \pm \frac{1}{4}$
3. $x < 2$
4. $x \in (-\infty, -3) \cup (1, \infty)$
- Domain, intercepts, asymptotes for given rational functions as above.