2x – 3y - 9z = 11
3x + 3z= – 5
-3x + y - 4z = 8
solve for x, y,z

Step-by-step explanation:

2x – 3y - 9z = 11   ... (1)

3x + 3z= – 5  (2)

-3x + y - 4z = 8  (3)

add (3) and (2) : y - z = 3   so : y = z+3    (*)

put this value in (1) : 2x-3(z+3) -9z = 11

2x-3z -9-9z = 11    so : 2x =12z+20

x = 6z+10   (**)

put this value in (2) : 3(6z+10)+3z = -5

18z+30+3z=-5

21z = -35  

z = -35/21= - 5/3

put this value in (*) and (**) you have x and y .

to find the total number of combinations, multiply the quantity of each item by each other:

2 pairs of shoes x 3 pairs of shorts = 6 different combinations.