Find the value of x and y in the simultaneous equation: 3x + y = 21; xy = 30

Points X and Y are 20km North and 9km East of point O, respectively. What is the bearing of Y from X? Correct to the nearest degree.

If \(P = (\frac{Q(R - T)}{15})^{\frac{1}{3}}\), make T the subject of the formula.

In the diagram above, O is the centre of the circle ABC, < ABO = 26° and < BOC = 130°. Calculate < AOC.

Each of the interior angles of a regular polygon is 140°. Calculate the sum of all the interior angles of the polygon.