a)
1.8+0.9=2.7
0.4+0.9=1.3
x+0.9=3.6>x=3.6-0.9>x=2.7
b)
34.16-6.82=27.34
x-6.82=82.7>x=82.7+6.82>x=89.52
x-6.82=9.78>x=9.78+6.82>x=16.6
