Question 652291
One of the things that you can do with equations in algebra, is check your answer
in the original problem, for instance if you get x = 4, replace x in the original
problem with 4 and see if equality is preserved, (right side value = left side value.) Do this for every equation problem that you have, both homework and in the final. You will find math mistakes and other errors this way. 
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If the problem is not an equation, an expression that you must simplify, then
assign a value (like 2) to the variables in the original expression, find the value. Do the same with your simplified expression, they should be equal
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Sometimes assigning a value of 2 will cause you to have a 0 in the denominator;
This of course is not allowed. Then assign another value like 3 and do the same 
thing