The expression given to us is:
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This can be rewritten as:
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Now, let us take
as the common factor in the first two terms in the numerator and 5 as the common factor in the last two terms in the numerator. Thus, we get:
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Now, taking
as the common factor, we get:
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The above is the simplest form of the given expression,
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As we know that the denominator of a rational expression can never be zero, thus the only restriction in our case will be:
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or,
(subtracting 3 from both sides)
Thus, the restriction is that
cannot be equal to
.