Answer: The correct answer is: " 2x² " .
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Explanation:
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We are asked: "What is the sum of: "x + x² + 2" and "x² − 2 − x" ? 
Since we are to find the "sum" ; 
 → We are to "add" these 2 (two) expressions together:
 → (x + x² + 2) + (x² − 2 − x) ;
Note: Let us rewrite the above, by adding the number "1" as a coefficient to: the values "x" ; and "x² " ; since there is an "implied coefficient of "1" ; 
 → {since: "any value" ; multiplied by "1"; results in that exact same value.}.
 → (1x + 1x² + 2) + (1x² − 2 − 1x) ;
Rewrite as: 
 → 1x + 1x² + 2) + (1x² − 2 − 1x) ;
Now, let us add the "coefficient" , "1" ; just before the expression: 
 "(1x² − 2 − 1x)" ; 
 {since "any value", multiplied by "1" , equals that same value.}.
And rewrite the expression; as follows:
 → (1x + 1x² + 2) + 1(1x² − 2 − 1x) ; 
Now, let us consider the following part of the expression:
 → " +1(1x² − 2 − 1x) " ;
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Note the distributive property of multiplication:
 → " a(b+c) = ab + ac " ; 
and likewise:
 → " a(b+c+d) = ab + ac + ad " .
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So; we have: 
 → " +1(1x² − 2 − 1x) " ; 
 = (+1 * 1x²) + (+1 *-2) + (+1*-1x) ; 
 = + 1x² + (-2) + (-1x) ; 
 = +1x² − 2 − 1x ; 
 ↔ ( + 1x² − 1x − 2)
Now, bring down the "left-hand side of the expression:
1x + 1x² + 2 ; 
and add the rest of the expression:
 → 1x + 1x² + 2 + 1x² − 1x − 2 ;
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Now, simplify by combining the "like terms" ; as follows:
 +1x² + 1x² = 2x² ;
 +1x − 1x = 0 ; 
 + 2 − 2 = 0 ; 
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The answer is:  " 2x² " . 
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Hope this is helpful to you!
 Best wishes!
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