Answer: The correr solution is 
Step-by-step explanation:
Since the steps in Lin's solution are not shown, we are not able to find her erros. However, we can solve it step by step and find the correct result:

Firstly, in the left part of the equation we have to multiply
by the numbers inside the parenthesis; and in the right side we have to solve first what is inside the parenthesis:

Adding similar terms in the left side and multiplying
by the number inside the parenthesis in the right side:

Isolating
:
This is the correct solution
The range of sin(x) is [-1,1].
No matter what the value of x,pi,pi/2,pi/4,pi/6,-pi/2,etc the value of sinx will always be between -1 and 1(both included)
Sorry, don't have time to do them right now but I know who does!
http://www.wolframalpha.com/widgets/view.jsp?id=ae438682ce61743f90d4693c497621b7
Just plug in 2 at a time.
Answer:
the least common denominator
Step-by-step explanation:
The least common denominator is that number. It is the least common multiple of the denominator values.
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Simply multiplying by the product of the denominators will eliminate fractions, but may require reduction of fractions in the answer. If the "fractions" are rational expressions, extraneous solutions may be introduced.