Question

The cost of 4 dozens penceles, 3 dozens pens and 2 dozens eraser is Rs.16. The cost of 2 dozens penceles, 4 dozens pens and 6 dozens erase is Rs.90 wheras the cost of 6 dozens pencils, 2 dozone pens and 3 dozens eraser is Rs.70 find the cost of each itomes per dozens by matrices

Answer 1

dozen of pencils --- x
dozen of pens ----- y
dozen of erasers --- z

4x + 3y + 2z = 16
2x + 4y + 6z = 90
6x + 2y + 3z = 70

Since you want it done by matrices, which for these nice equations would be overkill, I would find the inverse of
4 3 2
2 4 6
6 2 3 , then multiply that by

16
90
70

unfortunately, it solves to
x = 5
y = -18.4
z= 25.6

These answers don't make any sense, so there has to be something wrong with your typing