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17 votes
17 votes
Find k. ..................​

Find k. ..................​-example-1
User Pauljwilliams
by
2.6k points

2 Answers

21 votes
21 votes

Answer:

k = -10

Step-by-step explanation:

From the remainder theorem, we know that the remainder, 210, is equal to f(2).


f(2) = 210 ,


4(2)^3 - 3 k(2)^2+44(2) - 30 = 210


32 -12k + 88 - 30 = 210


90 - 12k = 210


-12k = 120


k = -10

User Txominpelu
by
3.1k points
22 votes
22 votes

Answer:

k = -10

Step-by-step explanation:

f(x) = 4x³ - 3kx² + 44x - 30

The divisor is:

  • (x - 2)

Set divisor to zero:

  • (x - 2) = 0
  • x = 2

Insert this into equation.

⇒ 4(2)³ - 3k(2)² + 44(2) - 30 = 210

⇒ 32 - 12k + 88 - 30 = 210

⇒ -12k + 90 = 210

⇒ -12k = 210 - 90

⇒ -12k = 120

⇒ k = 120/-12

⇒ k = -10

User Zerobasedindex
by
2.5k points