I have two different questions:
1) If you have 1.1x10^-1 g/L and I need my answer to be in g/mL, how do I convert that?
2) I have 31x^5=1.4x10^-85. What does x equal?
0.11 g/L x (1L/1000 mL) = ?? g/mL
Note how the units you don't want to keep cancel and the unit you want to keep stays.
31x^5 = 1.4E-85
x^5 = (1.4E-85/31)
x = (1.4E-85/31)1/5
x = punch in 1.4E-85 on the calculator, divide by 31, then raise that to the 0.2 power. (0.2 is 1/5 in decimal). I did that and obtained 5.38E-18 which I would round to 5.4E-18 to two significant figures.