5/7(2,8c-4(целых)1/5d)-2,4(5/6c-1,5d)

Question

5/7(2,8c-4(целых)1/5d)-2,4(5/6c-1,5d)

Answer 1

5/7*(28*с/10-21*d/5)-24/10*(5*c/6-15*d/10)=
=(5*28*c)/70-(5*21*d)/35-24*5*c/60+(24*15*d)/100=сокращаем
=2*с-3*d-2*с+3,6*d=0,6*d