No mathematics the most common way of solving an equation will be PEMDAS so the answer for your question will most likely be subtraction.
I believe distillation is used to separate solvents of different kind as long as it is heated to its boiling temp
Photochemical smong result from the interaction of pollution in the presence of sunlight. The photochemical smog is result of the <span> chemical reaction in the air between the sunlight, nitrogen oxides and volatile organic compounds.
</span>It is noticed as a brown haze above cities. <span>The negative effects are: production of chlorofluorocarbons (CFCs) increased UV radiation, irritation to the eyes, nose, and throat. </span>
