Assignment: 
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Answer: 
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Explanation: 
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[ Step One ] Follow PEMDAS Order Of Operations; Calculate Within Parenthesis
Note: 

[ Step Two ] Rewrite Equation

[ Step Three ] Calculate Within Parenthesis

[ Step Four ] Rewrite Equation

[ Step Five ] Calculate Exponents

[ Step Six ] Rewrite Equation

[ Step Seven ] Multiply

[ Step Eight ] Rewrite Equation

[ Step Nine ] Subtract

[ Step Ten ] Rewrite Equation

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Answer:
(x^4 - 9·x + 5·x^7) + (5·x - 10 + 3·x^4 - 2·x^2)
x^4 - 9·x + 5·x^7 + 5·x - 10 + 3·x^4 - 2·x^2
5·x^7 + x^4 + 3·x^4 - 2·x^2 - 9·x + 5·x - 10
5·x^7 + 4·x^4 - 2·x^2 - 4·x - 10
Answer:
The correct answer should be A not 100% sure
90 volume because 3 multiples by 30 = 90