Originally Posted by

**Batw**
You can solve it using linear algebra, e.g. you can bound the solution set of potential answers due the constraints.

Let X = sixpence’s level which is unknown

It takes 12.5 XP on average to go up a level so sixpence needs 12.5 * X or 12.5X amount of XP to level up.

We now can bound the solution at one end because:

12.5X = Sigma Energy * energy coefficient + Sigma Stamina * stamina coefficient + 4 * natural regen

where Sigma means total SPs allocated to energy or stamina.

The above equation cannot so we need a constraint and sixpence tells us if s/he waste 6,000 to 8,000 energy IF s/he levels up in 9 days. That is Constraint #1

Constraint #2 is LSI of 9.0 in 4 days.

The math problem is solve the equation subject to Constraint #1 and Constraint #2. If you did it right, you should triangulate the solution set because you have 1 equation with multiple unknowns but the two constraints limit the potential answers.

You could probably used Solver feature on Excel.