Answer :
First of all you group like terms
3.5y=16.2-1.8-0.9-9
3.5y=16.2-11.7
3.5y=4.5
Divide through by 3.5 to get y
3.5y/3.5=4.5/3.5
y=1.2857
3.5y=16.2-1.8-0.9-9
3.5y=16.2-11.7
3.5y=4.5
Divide through by 3.5 to get y
3.5y/3.5=4.5/3.5
y=1.2857