The coefficient is: "1" .
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Note: There is an "implied coefficient" of "1"; since "1", multiplied by any value, is equal to that exact same value; by convention, we eliminate the "1" as a coefficient.
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Further explanation:
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(x+p)(x−q) = x² − xq + px − pq ;
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(x+p)(x−q) = {using "FOIL" → "First, Outer, Inner, and Last" terms}:
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First: x*x = x² ;
Outer: x*(-q)= -xq ;
Inner: p*x = px ;
Last: p*(-q) = -pq
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(x + p)(x − q) = x² − xq + px − pq .
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