1. **Problem:** Find the equation of a straight line with gradient $m$ passing through a point $(x_1, y_1)$.
2. **Formula:** The point-slope form of a line is given by:
$$y - y_1 = m(x - x_1)$$
This formula is used to find the equation of a line when you know the gradient and a point on the line.
3. **Important rules:**
- The gradient $m$ is the slope of the line.
- $(x_1, y_1)$ is a point on the line.
- After substituting values, simplify to get the equation in slope-intercept form $y = mx + c$.
4. **Solve part (a):** Gradient $m=2$, point $(3,2)$
$$y - 2 = 2(x - 3)$$
$$y - 2 = 2x - 6$$
$$y = 2x - 6 + 2$$
$$y = 2x - 4$$
5. **Solve part (b):** Gradient $m=-1$, point $(2,1)$
$$y - 1 = -1(x - 2)$$
$$y - 1 = -x + 2$$
$$y = -x + 2 + 1$$
$$y = -x + 3$$
6. **Solve part (c):** Gradient $m=3$, point $(-2,0)$
$$y - 0 = 3(x + 2)$$
$$y = 3x + 6$$
7. **Solve part (d):** Gradient $m=-3$, point $(1,-2)$
$$y + 2 = -3(x - 1)$$
$$y + 2 = -3x + 3$$
$$y = -3x + 3 - 2$$
$$y = -3x + 1$$
8. **Solve part (e):** Gradient $m=3$, passes through origin $(0,0)$
$$y - 0 = 3(x - 0)$$
$$y = 3x$$
9. **Solve part (f):** Gradient $m=4$, point $(-1,-2)$
$$y + 2 = 4(x + 1)$$
$$y + 2 = 4x + 4$$
$$y = 4x + 4 - 2$$
$$y = 4x + 2$$
10. **Solve part (g):** Gradient $m=4$, point $(2,8)$
$$y - 8 = 4(x - 2)$$
$$y - 8 = 4x - 8$$
$$y = 4x - 8 + 8$$
$$y = 4x$$
11. **Solve part (h):** Gradient $m=-2$, point $(-6,4)$
$$y - 4 = -2(x + 6)$$
$$y - 4 = -2x - 12$$
$$y = -2x - 12 + 4$$
$$y = -2x - 8$$
12. **Solve part (i):** Gradient $m=2$, midpoint of $(1,3)$ and $(5,5)$
Midpoint coordinates:
$$x_m = \frac{1 + 5}{2} = 3, \quad y_m = \frac{3 + 5}{2} = 4$$
Equation:
$$y - 4 = 2(x - 3)$$
$$y - 4 = 2x - 6$$
$$y = 2x - 6 + 4$$
$$y = 2x - 2$$
13. **Solve part (j):** Gradient $m=\frac{1}{2}$, midpoint of $(0,0)$ and $(-6,4)$
Midpoint coordinates:
$$x_m = \frac{0 - 6}{2} = -3, \quad y_m = \frac{0 + 4}{2} = 2$$
Equation:
$$y - 2 = \frac{1}{2}(x + 3)$$
$$y - 2 = \frac{1}{2}x + \frac{3}{2}$$
$$y = \frac{1}{2}x + \frac{3}{2} + 2$$
$$y = \frac{1}{2}x + \frac{7}{2}$$
**Final answers:**
(a) $y = 2x - 4$
(b) $y = -x + 3$
(c) $y = 3x + 6$
(d) $y = -3x + 1$
(e) $y = 3x$
(f) $y = 4x + 2$
(g) $y = 4x$
(h) $y = -2x - 8$
(i) $y = 2x - 2$
(j) $y = \frac{1}{2}x + \frac{7}{2}$
Line Equations Af6173
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