Me! i have problems with this question

the mass of the empty box is 4/3 kg.

Step-by-step explanation:

The total mass (box plus 4 books and 2 files) is 2 kg

When half of the load is removed (2 books and 2 files) the mass is 1 3/20.

We have the following equation:

2 kg - (x/2)= 1 3/20 kg

Where x is the total mass of the load (4 books and 2 files)

This steps where followed to solve the equation:

2 -x/2 = (20-3)/20

40-10x=17

23=10x

x=2/3 kg

That is the total mass of the load

Hence

2kg -2/3 kg= 4/3 kg, the mass of the box

set each factor equal to 0

4x-3 = 0

2x-1 = 0

solve for x.

4x-3=0

4x=3

x= 3/4

solve for x. 

2x-1= 0

2x= 1

x= 1/2

your answer should be 1/2 is less than or equal to x and 3/4 is greater than or equal to x