Equation Solutions
1. Solve $3(2x - 1) - 2(x + 4) = 6$.
Expanding: $6x - 3 - 2x - 8 = 6$.
Simplify: $4x - 11 = 6$.
Add 11 to both sides: $4x = 17$.
Divide both sides by 4: $x = \frac{17}{4}$.
Answer: (a) $\frac{17}{4}$.
2. Solve $2(1 - 2x) - (x + 3) = 5(1 - x)$.
Expand: $2 - 4x - x - 3 = 5 - 5x$.
Simplify: $-1 - 5x = 5 - 5x$.
Add $5x$ to both sides: $-1 = 5$ (contradiction).
No solution here suggests re-check.
Actually, terms cancel: subtract left from right, $-1 - 5x - 5 + 5x = 0$ means $-6=0$ no, so only if $-1 -5x = 5 -5x$, reduce to $-1 = 5$ no, so no solution. Answer: (d) none.
3. Solve $\frac{3x - 5}{1 - 2x} = \frac{2}{3}$.
Cross multiply: $3(3x - 5) = 2(1 - 2x)$.
$9x - 15 = 2 - 4x$.
Add $4x$ to both sides: $13x - 15 = 2$.
Add 15: $13x = 17$.
Divide: $x = \frac{17}{13}$.
Answer: (c) $\frac{17}{13}$.
4. Solve $\frac{3}{x - 1} + 5 = \frac{7}{x - 1}$.
Bring terms with $x-1$ together:
$\frac{3}{x - 1} - \frac{7}{x - 1} = -5$.
Combine fractions: $\frac{-4}{x - 1} = -5$.
Invert and multiply: $-4 = -5(x - 1)$.
Divide both sides by -5: $\frac{4}{5} = x - 1$.
Add 1: $x = 1 + \frac{4}{5} = \frac{9}{5}$.
Answer: (b) $\frac{9}{5}$.
5. Solve $\frac{2x - 5}{3x + 7} = \frac{2x + 3}{3x}$.
Cross multiply:
$(2x - 5)(3x) = (2x + 3)(3x + 7)$.
$6x^2 - 15x = 6x^2 + 14x + 9x + 21$.
$6x^2 - 15x = 6x^2 + 23x + 21$.
Subtract $6x^2$:
$-15x = 23x + 21$.
Add $-23x$ to both sides:
$-38x = 21$.
Divide by -38:
$x = -\frac{21}{38}$.
Answer: (d) $-\frac{21}{38}$.
6. Solve $\frac{3}{x - 2} + \frac{4}{x + 2} = \frac{1}{x^2 - 4}$ with $x^2 - 4 = (x-2)(x+2)$.
Multiply both sides by $(x-2)(x+2)$:
$3(x+2) + 4(x-2) = 1$.
$3x + 6 + 4x - 8 = 1$.
$7x - 2 = 1$.
$7x = 3$.
$x = \frac{3}{7}$.
Answer: (c) $\frac{3}{7}$.
7. Solve $\frac{2x}{x - 3} - 2 = \frac{3}{x + 3}$.
Write as $\frac{2x}{x - 3} - 2 = \frac{3}{x + 3}$.
Multiply both sides by $(x-3)(x+3)$:
$2x(x+3) - 2(x-3)(x+3) = 3(x-3)$.
Expand:
$2x^2 + 6x - 2(x^2 - 9) = 3x - 9$.
$2x^2 + 6x - 2x^2 + 18 = 3x - 9$.
Simplify:
$6x + 18 = 3x - 9$.
Subtract $3x$:
$3x + 18 = -9$.
Subtract 18:
$3x = -27$.
$x = -9$.
Answer: (a) $-9$.
8. Find roots of $4x^2 + 9x - 17 = 0$.
Using quadratic formula:
$x = \frac{-9 \pm \sqrt{9^2 - 4 \times 4 \times (-17)}}{2 \times 4}$.
Calculate discriminant:
$81 + 272 = 353$.
Roots:
$x = \frac{-9 \pm \sqrt{353}}{8}$.
$\sqrt{353} \approx 18.79$.
$x_1 = \frac{-9 + 18.79}{8} = 1.223$.
$x_2 = \frac{-9 - 18.79}{8} = -3.473$.
Answer: (a) $1.223$ or $-3.473$.
9. Solve $6x^2 - 7x + 2 = 0$.
Use quadratic formula:
$x = \frac{7 \pm \sqrt{(-7)^2 - 4 \times 6 \times 2}}{2 \times 6}$.
Discriminant:
$49 - 48 = 1$.
Roots:
$x = \frac{7 \pm 1}{12}$.
$x_1 = \frac{8}{12} = \frac{2}{3} \approx 0.67$.
$x_2 = \frac{6}{12} = 0.5$.
Answer: (c) $0.67$ or $0.5$.
10. Solve system:
$3x - y = -2$ and $x - 3y = 10$.
From first: $y = 3x + 2$.
Substitute into second:
$x - 3(3x + 2) = 10$.
$x - 9x - 6 = 10$.
$-8x = 16$.
$x = -2$.
Then $y = 3(-2) + 2 = -6 + 2 = -4$.
Sum:
$x + y = -2 + (-4) = -6$.
Answer: (b) $-6$.