The prices of three commodities `P ,\ Q ,\ a n d\ R` are Rs `x ,\ y\ a n d\ z` per unit respectively. `A` purchases 4 units of `R` and sells 3 unit of `P` and 5 units of `Qdot` `B` purchases 3 units of `Q` and sells 2 units of `P` and 1 unit of `Rdot` `C` purchases 1 unit of `P` and sells 4 units of `Q` and 6 units of `Rdot` In the process `A ,\ B\ a n d\ C` earn Rs 6000, 5000 and 13000 respectively. If selling the units is positive earning and buying the units is negative earnings, find the price per unit of three commodities by using matrix method.