1.
0,(3)=3/9=1/3
0,25=1/4
x/3=k x=3k
y/4=k y=4k
(x+y)/2=14
x+y=28
3k+4k=28
7k=28
k=4
x=3*4=12
y=4*4=16
2.x+y=20
x/4=k x=4k
y/3=k y=3k
4k+3k=20
7k=20
k=20/7
x=4k=4*20/7=80/7
y=3k=3*20/7=60/7
3.
(x+y+z)/3=60
x+y+z=180
0,(3)=3/9=1/3
0,25=1/4
0,2=2/10=1/5
x/3=k x=3k
y/4=k y=4k
z/5=k z=5k
3k+4k+5k=180
12k=180
k=15
x=3k=3*15=45
y=4k=4*15=60
z=5k=5*15=75