SOLUTION: Determine the value of k so that x^2 –3x – 4k divides x^3 –37x –12k

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Question 252123: Determine the value of k so that x^2 –3x – 4k divides x^3 –37x –12k
Found 2 solutions by drk, edjones:
Answer by drk(1908) About Me  (Show Source):
You can put this solution on YOUR website!
To solve this problem, we want to use polynomial division. On the outside you will write x%5E2-3x-4k and on the inside you will write x%5E3+%2B+0x%5E2+-37x+-12k. Notice that there is a 0x^2. This is because we jumped over the x^2 term. Now we are ready to divide.
In the first division run through, we place an x above the x^3 term. By distributive property, we get x%5E3+-3x%5E2+-4kx. Now by subtraction, your new level of terms is 3x%5E2+-+37x+%2B+4kx. Bring down the -12k and redivide. This time we place a 3 above the 0x^2 term and distribute as before to get
3x%5E2+-+9x+-+12k. This subtracts nicely to get -28x + 4kx. The remainder must be zero, so
-28x - 4kx = 0. K = -7.

Answer by edjones(8007) About Me  (Show Source):
You can put this solution on YOUR website!
....................... x+3
...............-------------------------
x^2-3x-4k/x^3..........-37x-12k
.....................x^3-3x^2-4kx
..............--------------------------
............................3x^2-9x-12k
.
.
-37x-(-4kx)=-9x
-37+4k=-9 divide each side by x.
4k=37-9
4k=28
k=7
.
Ed