Answers
Correct Question:
What should be subtracted from 3x³ - 8x² + 4x - 3, so that the resulting expression has (x + 2) as a factor?
Solution:
Let k be the required number.
f(x) = 3x³ - 8x² + 4x - 3 - k
Applying Factor theorem,
(x + 2) = 0
⇒ x = -2
Since (x + 2) is a factor,
f(-2) = 0
Now, Substituting x as -2.
f(-2) = 3(-2)³ - 8(-2)² + 4(-2) - 3 - k
⇒ 0 = 3(-8) - 8(4) - 8 - 3 - k
⇒ 0 = -24 - 32 - 8 - 3 - k
⇒ 0 = -67 - k
∴ k = -67
Alternate method:
On dividing 3x³ - 8x² + 4x - 3 by (x + 2),
x + 2 ) 3x³ - 8x² + 4x - 3 ( 3x² - 14x + 32
[-] 3x³ + 6x²
- 14x² + 4x
[-] - 14x² - 28x
32x - 3
[-] 32x + 64
-67
∴ -67 should be subtracted.
We get the same answer in both the methods.
Answer:
=>0=-67-a
Step-by-step explanation:
The simplification is in the attachment..
Hope it's help you didi