SOLUTION: If x^2 - 3x + 2k is divided by x+2, the remainder is 7. What is k? Thank you.

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Question 1011717: If x^2 - 3x + 2k is divided by x+2, the remainder is 7. What is k? Thank you.
Found 2 solutions by ankor@dixie-net.com, MathTherapy:
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
If x^2 - 3x + 2k is divided by x+2, the remainder is 7. What is k?
:
using synthetic division
......_______________
-2 |1 - 3 + 2k
.........- 2 + 10
......----------
..,,...1 - 5 + 7
then we can write the equation
2k + 10 = 7
2k = 7 - 10
2k = -3
k = -1.5
:
Our equation is: x^2 - 3x - 3

Answer by MathTherapy(10552) About Me  (Show Source):
You can put this solution on YOUR website!

If x^2 - 3x + 2k is divided by x+2, the remainder is 7. What is k? Thank you.
Since x + 2 is a factor, we can say that: x + 2 = 0 -------> x = - 2
f%28x%29+=+ax%5E2+%2B+bx+%2B+c ------------ Remainder Theorem
f%28-+2%29+=+%28-+2%29%5E2+-+3%28-+2%29+%2B+2k --- Substituting - 2 for x in remainder theorem
7 = 4 + 6 + 2k -------------- Substituting 7 for f(- 2), and simplifying equation
7 = 10 + 2k
7 - 10 = 2k
- 3 = 2k
highlight_green%28%28-+3%29%2F2%29+=+k OR highlight_green%28k+=+-+1.5%29