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Im struggling with the -4cd^4 term i cant seem to find its actual addend thank u

Im struggling with the -4cd^4 term i cant seem to find its actual addend thank u-example-1
User Titibouboul
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1 Answer

19 votes
19 votes

We are given the result of adding two polynomials is:


8d^5-3c^3d^2+5c^2d^3-4cd^4+9

One of the polynomials that is added is:


2d^5-c^3d^2+8cd^4+1

To determine the polynomial that was added we will use a polynomial with the same variables that appear on each polynomial but with unknown coefficients, like this:


2d^5-c^3d^2+8cd^4+1+(xd^5+yc^3d^2+wc^2d^3+zcd^4+u)

Now we associate like terms:


(2+x)d^5+(-1+y)c^3d^2+wc^2d^3+(8+z)cd^4+(1+u)

Now, each of the new coefficients must be equal to the coefficients in the resulting polynomial, therefore, we have for the first term:


\begin{gathered} 2+x=8 \\ x=8-2 \\ x=6 \end{gathered}

For the second term:


\begin{gathered} -1+y=-3 \\ y=-3+1 \\ y=-2 \end{gathered}

For the third term:


\begin{gathered} w=5 \\ \end{gathered}

For the fourth term:


\begin{gathered} 8+z=-4 \\ z=-4-8 \\ z=-12 \end{gathered}

For the last term:


\begin{gathered} 1+u=9 \\ u=9-1 \\ u=8 \end{gathered}

Now that we have the coefficients we can substitute in the polynomial we added, we get:


6d^5-2c^3d^2+5c^2d^3-12cd^4+8

User SLDem
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