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Rewrite the expression 7x^4+x+14/x+2 in the form q(x)+r(x)/b(x)

User Shila
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1 Answer

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7x^4=7x^3\cdot x, and
7x^3(x+2)=7x^4+14x^3. Subtract this from the numerator and you get a remainder of


(7x^4+x+14)-(7x^4+14x^3)=-14x^3+x+14


-14x^3=-14x^2\cdot x, and
-14x^2(x+2)=-14x^3-27x^2. Subtract this from the previous remainder and you get a new remainder of


(-14x^3+x+14)-(-14x^3-27x^2)=27x^2+x+14


27x^2=27x\cdot x, and
27x(x+2)=27x^2+54x. Subtract this from the previous remainder and you get a new one of


(27x^2+x+14)-(27x^2+54x)=-53x+14


-53x=-53\cdot x, and
-53(x+2)=-53x-106. Subtract this from the previous remainder and you get a new one of


(-53x+14)-(-53x-106)=120


x doesn't divide 120, so we're done, and putting everything together we've shown that


(7x^4+x+14)/(x+2)=7x^3-(14x^3-x-14)/(x+2)


(7x^4+x+14)/(x+2)=7x^3-14x^2+(27x^2+x+14)/(x+2)


(7x^4+x+14)/(x+2)=7x^3-14x^2+27x-(53x+14)/(x+2)


(7x^4+x+14)/(x+2)=\underbrace{7x^3-14x^2+27x-53}_(q(x))+\underbrace{(120)/(x+2)}_(r(x)/b(x))

User Paul Morie
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