Question

Помогите решить два уравнения

Answer 1

2 1/6-11/15с=0,15
13/6-11/15с=15/100=3/20
11/15с=13/6-3/20=(130-9)/60=121/60
11/15с=121/60
с=121/60:11/15=121/60*15/11=11/4=2 3/4
с=2 3/4

0,25z-1 1/6=2 1/3
5/20z-7/6=7/3
5/20z=7/3+7/6=(14+7)/6=21/6=7/2
5/20z=7/2
z=7/2:5/20=7/2*20/5=70/5=14
z=14

Answer 2

11/15c=13/6-3/20
11/15c=130/60-9/60
11/15c=121/60
c=121/60 11/15
c=11/4