3 oranges = 1 apple +2 lychees 2

The result of subtraction is 1 apple =5 lychees.

Replace 3 oranges with 2 =5 lychees +2 lychees =7 lychees.

4 ballpoint pens =2 pens = 1 pen+1 pen +4 pencils.

1 pen =2 ballpoint pens

1 pen+1/2 pen +4 pencils =2 pens.

4 pencils = 1/2 pens

1 pen =8 pencils