Question 268437: when x^7- 2x^4 + 5x^3 +x-9 is multiplied by -3x^6-3x^4 + 4x^3-5x^2 +1 and the like terms are combined , what is the coefficient of x^4?
Answer by persian52(161)   (Show Source):
You can put this solution on YOUR website! x^(7)-2x^(4)+5x^(3)+x-9*-3x^(6)-3x^(4)+4x^(3)-5x^(2)+1
Multiply -9 by -3x^(6) to get 27x^(6).
x^(7)-2x^(4)+5x^(3)+x+27x^(6)-3x^(4)+4x^(3)-5x^(2)+1
Since -2x^(4) and -3x^(4) are like terms, subtract 3x^(4) from -2x^(4) to get -5x^(4).
x^(7)-5x^(4)+5x^(3)+x+27x^(6)+4x^(3)-5x^(2)+1
Since 5x^(3) and 4x^(3) are like terms, add 4x^(3) to 5x^(3) to get 9x^(3).
x^(7)-5x^(4)+9x^(3)+x+27x^(6)-5x^(2)+1
Reorder the polynomial x^(7)-5x^(4)+9x^(3)+x+27x^(6)-5x^(2)+1 alphabetically from left to right, starting with the highest order term.
Answer:x^(7)+27x^(6)-5x^(4)+9x^(3)-5x^(2)+x+1
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coefficient of x^4?
Answer: -5x^(4)
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There you go! ☺
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