Answer :

subtract (10 divided into fifths) from (20 divided into half)
= (20 divided into half) - (10 divided into fifths)
= (20 / 2) - (10 / 5)

If you need to solve the expression:
= 10 - 2
= 8

Hope this helps! :)

subtract (10 divided into fifths) from (20 divided into half)
= (20 divided into half) - (10 divided into fifths)
= (20 / 2) - (10 / 5)
    10              2

10 - 2 = 8

Hope that helps you. :-)