If y + 2x = 4 and y - 3x = -1, find the value of (x + y)

If x : y : z = 2 : 3 : 4, evaluate \(\frac{9x + 3y}{6z - 2y}\)

Simplify; \(\frac{2 - 18m^2}{1 + 3m}\)

A curve is such that when y = 0, x = -2 or x = 3. Find the equation of the curve.

The volume of a cylindrical tank, 10m high is 385 m\(^2\). Find the diameter of the tank. [Take \(\pi = \frac{22}{7}\)]