1. **State the problem:** Solve the system of equations for $x$ and $y$:
$$\begin{cases} x^2 + xy - y^2 + 3x = -4 \\ 2x^2 + 2xy - 2y^2 + 5x - y = -6 \end{cases}$$
2. **Rewrite the system:**
$$\begin{cases} x^2 + xy - y^2 + 3x + 4 = 0 \\ 2x^2 + 2xy - 2y^2 + 5x - y + 6 = 0 \end{cases}$$
3. **Divide the second equation by 2** to simplify coefficients:
$$x^2 + xy - y^2 + \frac{5}{2}x - \frac{y}{2} + 3 = 0$$
4. **Subtract the first equation from this simplified second equation**:
$$\left(x^2 + xy - y^2 + \frac{5}{2}x - \frac{y}{2} + 3\right) - \left(x^2 + xy - y^2 + 3x + 4\right) = 0$$
Simplify:
$$\frac{5}{2}x - \frac{y}{2} + 3 - 3x - 4 = 0$$
$$\left(\frac{5}{2}x - 3x\right) - \frac{y}{2} + (3 - 4) = 0$$
$$-\frac{1}{2}x - \frac{y}{2} - 1 = 0$$
Multiply both sides by $-2$:
$$x + y + 2 = 0$$
5. **Express $y$ in terms of $x$:**
$$y = -x - 2$$
6. **Substitute $y$ into the first original equation:**
$$x^2 + x(-x - 2) - (-x - 2)^2 + 3x = -4$$
Simplify step-by-step:
- $x^2 + x(-x - 2) = x^2 - x^2 - 2x = -2x$
- $(-x - 2)^2 = (x + 2)^2 = x^2 + 4x + 4$
So the equation becomes:
$$-2x - (x^2 + 4x + 4) + 3x = -4$$
Simplify:
$$-2x - x^2 - 4x - 4 + 3x = -4$$
$$-x^2 - 3x - 4 = -4$$
7. **Add 4 to both sides:**
$$-x^2 - 3x = 0$$
8. **Multiply both sides by -1:**
$$x^2 + 3x = 0$$
9. **Factorize:**
$$x(x + 3) = 0$$
10. **Solve for $x$:**
$$x = 0 \quad \text{or} \quad x = -3$$
11. **Find corresponding $y$ values using $y = -x - 2$:**
- If $x=0$, then $y = -0 - 2 = -2$
- If $x=-3$, then $y = -(-3) - 2 = 3 - 2 = 1$
12. **Final solutions:**
$$\boxed{(0, -2) \quad \text{and} \quad (-3, 1)}$$
Solve System 162
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