Simplify $$\frac{3x^2+27x}{x+8}\div\frac{x^2+8x-9}{5x+40}$$

$$\frac{x^2-4}{x^2+2x}\div\left(6x-12\right)=\frac{1}{6x}$$

True or False?

Given a volume of a geometry is $$V=\frac{2}{3}\pi r^3+\pi r^2h$$ .

Find the value of h when $$\pi=\frac{22}{7},\ V=1488\frac{2}{3},\ r=7$$ .

The following diagram shows a window. The top part is a rectangle with length x cm and height y cm while the bottom part is a square with side x cm.

Express the total area of the window, in A cm² in terms of x and y.

[Area of quadrilateral = $$Length\times Width$$ ]

Given that $$y^2=5+2x^2$$ , express x in terms of y.

Solve the following simultaneous equation.

$$2x+7y=4$$

$$5y-6x=40$$

The following figure shows a basketball with a radius of 7.5 cm. Calculate the volume of the ball and give the answer to 2 decimal points by using $$\pi=3.142$$ .

[Volume of sphere = $$\frac{4}{3}\pi r^3$$ ]

The following diagram shows a straight line passes through point P and point Q.

Find the equation of the straight line.