Data Sufficiency for Equations, Inequalities and VICs

Things one must know:

• Solved through algebraic manipulations. Sometimes you will need to manipulate the original equation, other times you will need to manipulate the statements, sometimes both. Remember MADS.
• As you rephrase, always keep in mind the variable or variable combo you are trying to isolate.
• Sometimes, even when the variables have multiple potential values, the answer to the question stays the same.
• Frequently, the combos are "hidden": they are not asked about directly, in these cases, you must rephrase the question to find the hidden combo.
• Be on the lookout for hidden meaning in certain statements as you rephrase a question. Sometimes a particular piece of information has an intuitive interpretation that you will not see by simply plodding through the algebra.