1)15x=0.15
x=0.15/15
x=0.01
2)3a+8a=1.87
11a=1.87
a=1.87/11
a=0.17
3)7z-3z=5.12
4z=5.12
z=5.12/4
z=1.28
2, 21.3, 1/4, 5/9, 2, 1/4, 0, 21.3, 5/9