Răspuns:
Explicație pas cu pas:
a)8........................20
12.......................y=12×20/8=3×5=15
b( 8..............................20
x.................................30
x=30×8/20=3×4=12
c) 8...............................20
2...............................y=2×20/8=20/4=5
d) 8...............................20
x.................................0,9
x=8×0,9/20=0,36