Complex Number Solution
1. **State the problem:** We are given a complex number $z = x + iy$ that satisfies the equation $$\frac{z}{z+2} = 2 - i.$$ We want to find the values of $x$ and $y$.
2. **Write the equation explicitly:** Substitute $z = x + iy$ into the equation:
$$\frac{x + iy}{(x + iy) + 2} = 2 - i.$$
3. **Simplify the denominator:**
$$(x + iy) + 2 = (x + 2) + iy.$$
4. **Set up the equation:**
$$\frac{x + iy}{(x + 2) + iy} = 2 - i.$$
5. **Multiply both sides by $((x + 2) + iy)$ to clear the denominator:**
$$x + iy = (2 - i)((x + 2) + iy).$$
6. **Expand the right side using distributive property:**
$$(2 - i)((x + 2) + iy) = 2(x+2) + 2iy - i(x+2) - i(iy).$$
7. **Calculate each term:**
$2(x+2) = 2x + 4$
$2iy = 2iy$
$-i(x+2) = -ix - 2i$
$-i(iy) = -i^2y = y$ (because $i^2 = -1$)
8. **Combine the terms:**
$$(2x + 4) + 2iy - ix - 2i + y = (2x + 4 + y) + (2y - x - 2)i.$$
9. **Equate the real and imaginary parts from both sides:**
Real parts: $x = 2x + 4 + y$
Imaginary parts: $y = 2y - x - 2$
10. **Solve the real part equation:**
$$x = 2x + 4 + y \implies x - 2x - y = 4 \implies -x - y = 4 \implies x + y = -4.$$
11. **Solve the imaginary part equation:**
$$y = 2y - x - 2 \implies y - 2y = - x - 2 \implies -y = - x - 2 \implies y = x + 2.$$
12. **Substitute $y = x + 2$ into $x + y = -4$: **
$$x + (x + 2) = -4$$
$$2x + 2 = -4$$
$$2x = -6$$
$$x = -3.$$
13. **Find $y$ using $y = x + 2$: **
$$y = -3 + 2 = -1.$$
**Final answer:** $x = -3$ and $y = -1$.