1. **State the problem:** Solve the system of linear equations:
$$3x + 9y = 0$$
$$5x - 6y = 38$$
2. **Formula and rules:** We can solve this system using substitution or elimination. Here, we use elimination to eliminate one variable.
3. **Multiply the first equation by 2 and the second by 3 to align coefficients of $y$:**
$$2(3x + 9y) = 2(0) \Rightarrow 6x + 18y = 0$$
$$3(5x - 6y) = 3(38) \Rightarrow 15x - 18y = 114$$
4. **Add the two equations to eliminate $y$:**
$$6x + 18y + 15x - 18y = 0 + 114$$
$$6x + 15x + \cancel{18y} - \cancel{18y} = 114$$
$$21x = 114$$
5. **Solve for $x$:**
$$x = \frac{114}{21} = \frac{\cancel{114}^{6} \times 19}{\cancel{21}^{3} \times 7} = \frac{38}{7}$$
6. **Substitute $x = \frac{38}{7}$ into the first equation to find $y$:**
$$3\left(\frac{38}{7}\right) + 9y = 0$$
$$\frac{114}{7} + 9y = 0$$
7. **Isolate $y$:**
$$9y = -\frac{114}{7}$$
$$y = \frac{-\frac{114}{7}}{9} = -\frac{114}{7} \times \frac{1}{9} = -\frac{114}{63}$$
8. **Simplify $y$:**
$$y = -\frac{\cancel{114}^{6} \times 19}{\cancel{63}^{9} \times 7} = -\frac{38}{21}$$
**Final answer:**
$$x = \frac{38}{7}, \quad y = -\frac{38}{21}$$
Solve Linear System 6Aed3F
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