The answer is: [A]: " 8m − 3 " .
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Step-by-step explanation:
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(m² + 5m − 7) − (m² − 3m − 4) =
(m² + 5m − 7) − 1(m² − 3m − 4) =
(m² + 5m − 7) − 1m² + 3m + 4) =
m² + 5m − 7 − m² + 3m + 4 ;
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Now, combine the "like terms" :
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m² − m² = 0 (cancel out).
+5m +3m = +8m ;
− 7 + 4 = -3 ;
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And we are left with:
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" 8m − 3 " ; which is: Answer choice: [A] .
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