1. **State the problem:**
We are given two lines, l and k, and need to draw them on a coordinate diagram, find their intersection point R, and then find the area of triangle RST formed by points R and the x-intercepts S and T of lines l and k.
2. **Find the equations of lines l and k:**
(Since the user did not provide explicit equations, we assume they are given or need to be found from context. For demonstration, let's assume line l: $y = m_1x + c_1$ and line k: $y = m_2x + c_2$.)
3. **Find the point of intersection R:**
Set the two line equations equal to find $x$:
$$m_1x + c_1 = m_2x + c_2$$
Rearranged:
$$m_1x - m_2x = c_2 - c_1$$
$$x(m_1 - m_2) = c_2 - c_1$$
Divide both sides by $m_1 - m_2$ (assuming $m_1 \neq m_2$):
$$x = \frac{c_2 - c_1}{m_1 - m_2}$$
Substitute $x$ back into either line equation to find $y$:
$$y = m_1 \times x + c_1$$
4. **Find x-intercepts S and T:**
Set $y=0$ in each line equation:
For line l:
$$0 = m_1x + c_1 \Rightarrow x = -\frac{c_1}{m_1}$$
For line k:
$$0 = m_2x + c_2 \Rightarrow x = -\frac{c_2}{m_2}$$
Points:
$$S = \left(-\frac{c_1}{m_1}, 0\right), \quad T = \left(-\frac{c_2}{m_2}, 0\right)$$
5. **Calculate area of triangle RST:**
Using the formula for area of triangle with vertices $(x_1,y_1)$, $(x_2,y_2)$, $(x_3,y_3)$:
$$\text{Area} = \frac{1}{2} \left| x_1(y_2 - y_3) + x_2(y_3 - y_1) + x_3(y_1 - y_2) \right|$$
Substitute:
$$R = (x_R, y_R), S = \left(-\frac{c_1}{m_1}, 0\right), T = \left(-\frac{c_2}{m_2}, 0\right)$$
Area:
$$= \frac{1}{2} \left| x_R(0 - 0) + \left(-\frac{c_1}{m_1}\right)(0 - y_R) + \left(-\frac{c_2}{m_2}\right)(y_R - 0) \right|$$
$$= \frac{1}{2} \left| \frac{c_1}{m_1} y_R - \frac{c_2}{m_2} y_R \right| = \frac{1}{2} |y_R| \left| \frac{c_1}{m_1} - \frac{c_2}{m_2} \right|$$
**Summary:**
- Find intersection $R$ by solving line equations.
- Find x-intercepts $S$ and $T$ by setting $y=0$.
- Calculate area of triangle $RST$ using the formula above.
Since no explicit line equations were provided, this is the general method to solve the problem.
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**Question 2(a):**
Given circle equation:
$$ (x - 4)^2 + (y + 3)^2 = 25 $$
- Centre is at $(4, -3)$.
- Radius is $\sqrt{25} = 5$.
**Question 2(b):**
Check if point $P(7, -7)$ lies on the circle:
Substitute into circle equation:
$$ (7 - 4)^2 + (-7 + 3)^2 = 3^2 + (-4)^2 = 9 + 16 = 25 $$
Since left side equals right side, point $P$ lies on the circle.
Lines Intersection 5Bd76F
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