Question

Simplify the following expression and state the excluded values m+7/m^2+4m-21

Answer 1

Answer:     1 / (m−3) ;  m ≠ -3, 7 .
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Explanation:
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Given:
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(m+7) / (m² + 4m − 21) ; Simplify the expression ;
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In the "denominator" :  " m² + 4m − 21 "  ; see if we can factor out an 
  "(m+7)" which is in the 'numerator' ;
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        m² + 4m − 21 = (m+7) (m−3) ;  Yes!
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So, rewrite the original problem as:
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       (m+7) / [(m+7)(m−3)] ; and the "(m−7)" in both the numerator AND the denominator "cancel out" to "1";  since anything divided by that same number equals "1" ;
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So we rewrite the expression:
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   1 / (m−3) ; m ≠ -3, 7 .
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Answer 2

5m-14/(m+1)(m-1)

excluded values: 1,-1