Find the equation of a straight line whose gradient is 3 and passes through point C(-2, 5).

Given gradient $m = 3$.
Given point $(x_1, y_1) = (-2, 5)$.

Substitute the values:

Add 5 to both sides:

The equation of the straight line is $\boxed*{y = 3x + 11}*$.

39 Use a number line to represent the inequality.

The inequality to be represented is not provided in the image. Therefore, it is not possible to represent it on a number line.

40 Find the perimeter of the figure below.

For a rectangle, opposite sides are equal. From the diagram, the lengths are $(3x+7)m$ and $(4x-10)m$, and the width is $(2x+5)m$.
Set the expressions for the length equal to each other to find $x$:

Subtract $3x$ from both sides:

Add 10 to both sides:

Length $L = 3x + 7 = 3(17) + 7 = 51 + 7 = 58$ m.
Width $W = 2x + 5 = 2(17) + 5 = 34 + 5 = 39$ m.

The perimeter $P$ of a rectangle is given by $P = 2(L + W)$.

The perimeter of the figure is $\boxed*{194 \text{ m}}*$.

41 Solve for y in: $\frac{1}{2}y - 5 = 7$.

The value of $y$ is $\boxed{24}$.

42 Find the gradient of the line shown.

The points are $(-2,-3)$ and $(8,4)$.
Let $(x_1, y_1) = (-2,-3)$ and $(x_2, y_2) = (8,4)$.

The gradient $m$ is given by:

The gradient of the line is $\boxed*{\frac{7}{10}}*$.

43 Find the gradient of the line shown below points C(-2, -3) and (8, 7).

The points are $C(-2,-3)$ and $(8,7)$.
Let $(x_1, y_1) = (-2,-3)$ and $(x_2, y_2) = (8,7)$.

The gradient of the line is $\boxed{1}$.