1. **Problem:** Solve the first pair of simultaneous equations:
$$\frac{1}{2}x + \frac{2}{3}y = 6 \frac{1}{5}$$
$$\frac{4}{3}x - \frac{1}{5}y = 13 \frac{3}{5}$$
2. **Convert mixed numbers to improper fractions:**
$$6 \frac{1}{5} = \frac{31}{5}, \quad 13 \frac{3}{5} = \frac{68}{5}$$
3. **Rewrite the system:**
$$\frac{1}{2}x + \frac{2}{3}y = \frac{31}{5}$$
$$\frac{4}{3}x - \frac{1}{5}y = \frac{68}{5}$$
4. **Eliminate fractions by multiplying each equation by the least common denominator (LCD):**
- For the first equation, LCD is 30:
$$30 \times \left(\frac{1}{2}x + \frac{2}{3}y\right) = 30 \times \frac{31}{5}$$
$$15x + 20y = 186$$
- For the second equation, LCD is 15:
$$15 \times \left(\frac{4}{3}x - \frac{1}{5}y\right) = 15 \times \frac{68}{5}$$
$$20x - 3y = 204$$
5. **System now:**
$$15x + 20y = 186$$
$$20x - 3y = 204$$
6. **Multiply first equation by 3 and second by 20 to align coefficients of $y$ for elimination:**
$$3 \times (15x + 20y) = 3 \times 186 \Rightarrow 45x + 60y = 558$$
$$20 \times (20x - 3y) = 20 \times 204 \Rightarrow 400x - 60y = 4080$$
7. **Add the two equations to eliminate $y$:**
$$45x + 60y + 400x - 60y = 558 + 4080$$
$$445x = 4638$$
8. **Solve for $x$:**
$$x = \frac{4638}{445}$$
9. **Substitute $x$ back into one of the original equations, e.g., $15x + 20y = 186$:**
$$15 \times \frac{4638}{445} + 20y = 186$$
10. **Calculate:**
$$\frac{15 \times 4638}{445} + 20y = 186$$
$$\frac{69570}{445} + 20y = 186$$
11. **Isolate $y$:**
$$20y = 186 - \frac{69570}{445}$$
12. **Convert 186 to fraction with denominator 445:**
$$186 = \frac{186 \times 445}{445} = \frac{82770}{445}$$
13. **Calculate:**
$$20y = \frac{82770}{445} - \frac{69570}{445} = \frac{13200}{445}$$
14. **Solve for $y$:**
$$y = \frac{13200}{445 \times 20} = \frac{13200}{8900} = \frac{132}{89}$$
15. **Final answers:**
$$x = \frac{4638}{445} \approx 10.42, \quad y = \frac{132}{89} \approx 1.48$$
Simultaneous Equations 581B77
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