Please answer using linear algebra/matricies

A region of land undergoes a succession. Grassland to shrubland to forest. Some of the forest is cleared and the cleared land reverts to grassland and shrubland. Each year 20% of the grassland is succeeded by shrubland and 10% of the shrubland is succeeded by forest. Each year 40% of the forest is cleared reverting to 75% grassland and 25% shrubland.

a) At the end of a year the land was 36% grassland, 37% shrubland and 27% forest. What is the distribution of grassland, shrubland and forest at the beginning of the year?

I would like to see the matrices that and how it is used to solve the equation. Also i do not understand how the equations are derived in terms of x y and z for forest, grassland and shrubland. Please explain the full steps without skipping thanks