1. **State the problem:** Solve the system of linear equations:
$$3x - y = -4$$
$$\frac{1}{4}x - \frac{1}{3}y = \frac{7}{4}$$
2. **Use substitution or elimination method.** Here, we use elimination.
3. Multiply the second equation by 12 (the least common multiple of denominators 4 and 3) to clear fractions:
$$12 \times \left(\frac{1}{4}x - \frac{1}{3}y\right) = 12 \times \frac{7}{4}$$
which simplifies to:
$$3x - 4y = 21$$
4. Now the system is:
$$3x - y = -4$$
$$3x - 4y = 21$$
5. Subtract the first equation from the second to eliminate $3x$:
$$\cancel{3x} - 4y - (\cancel{3x} - y) = 21 - (-4)$$
which simplifies to:
$$-4y + y = 21 + 4$$
$$-3y = 25$$
6. Solve for $y$:
$$y = \frac{25}{-3} = -\frac{25}{3}$$
7. Substitute $y = -\frac{25}{3}$ into the first equation:
$$3x - \left(-\frac{25}{3}\right) = -4$$
which is:
$$3x + \frac{25}{3} = -4$$
8. Subtract $\frac{25}{3}$ from both sides:
$$3x = -4 - \frac{25}{3} = -\frac{12}{3} - \frac{25}{3} = -\frac{37}{3}$$
9. Divide both sides by 3:
$$x = \frac{-\frac{37}{3}}{3} = -\frac{37}{3} \times \frac{1}{3} = -\frac{37}{9}$$
**Final answer:**
$$x = -\frac{37}{9}, \quad y = -\frac{25}{3}$$
Linear System 2177A3
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