To determine which option demonstrates that polynomials are a closed system under addition, we need to confirm the correct calculation for the sum of the two polynomials given.
Let's calculate the sum of the two polynomials:
- First polynomial: \( 0.923x^2 - 6.42x + 2.98 \)
- Second polynomial: \( 2.98 - 6.42x + 0.923x^2 \)
Now let's add them together:
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Combine the \( x^2 \) terms: \[ 0.923x^2 + 0.923x^2 = 1.846x^2 \]
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Combine the \( x \) terms: \[ -6.42x - 6.42x = -12.84x \]
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Combine the constant terms: \[ 2.98 + 2.98 = 5.96 \]
Thus, the sum of the two polynomials is: \[ 1.846x^2 - 12.84x + 5.96 \]
Looking at the provided responses, we see:
- The correct response that matches our calculation is: \[ (0.923x^2−6.42x+2.98)+(2.98−6.42x+0.923x^2)=1.846x^2−12.84x+5.96 \]
Therefore, the correct response that shows that polynomials are a closed system under addition is:
(0.923x^2−6.42x+2.98)+(2.98−6.42x+0.923x^2)=1.846x^2−12.84x+5.96