The correct answer is: [A]: " 4x³ + x² + x + 3 " .
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Explanation:
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(3x³ + 2x² + 2x + 1) + (x³ − x² − x + 2) =
↔ (x³ − x² − x + 2) + (3x³ + 2x² + 2x + 1) =
(x³ − x² − x + 2) + (3x³ + 2x² + 2x + 1) =
x³ − x² − x + 2 + 3x³ + 2x² + 2x + 1 ;
Combine the "like terms" ;
x³ + 3x³ = + 4x³ ;
−x² + 2x² = + x² ;
− x + 2x = + x ;
+ 2 + 1 = + 3 ;
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And rewrite:
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→ " 4x³ + x² + x + 3 " ;
→ which is: "Answer choice: [A]: " 4x³ + x² + x + 3 " .
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