ok well to solve any equation you do the opposite on each side.
for example 3x+5= 14
if i want to get x by itself i would subtract 5 from each side and divide 3 on each side.
x=3
when using decimals you would do the exact same thing. decimals are just numbers too.
if you had a certain equation in mind that you need help with let me know and i would be happy to solve it!