Question: Simultaneous equation questions and answers and surds
1. **Problem Statement:** Solve the simultaneous equations involving surds.
2. **General Approach:** To solve simultaneous equations, we use substitution or elimination methods. When surds are involved, treat them as algebraic terms and simplify carefully.
3. **Example Problem:** Solve the system:
$$\begin{cases} x + y = 3 \\ x - y = \sqrt{5} \end{cases}$$
4. **Step 1: Add the two equations to eliminate $y$:**
$$ (x + y) + (x - y) = 3 + \sqrt{5} $$
$$ 2x = 3 + \sqrt{5} $$
$$ x = \frac{3 + \sqrt{5}}{2} $$
5. **Step 2: Substitute $x$ back into the first equation to find $y$:**
$$ \frac{3 + \sqrt{5}}{2} + y = 3 $$
$$ y = 3 - \frac{3 + \sqrt{5}}{2} $$
$$ y = \frac{6 - (3 + \sqrt{5})}{2} = \frac{3 - \sqrt{5}}{2} $$
6. **Final Answer:**
$$ x = \frac{3 + \sqrt{5}}{2}, \quad y = \frac{3 - \sqrt{5}}{2} $$
This method can be applied to other simultaneous equations involving surds by carefully isolating variables and simplifying expressions.