Answer:
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Step-by-step explanation:

The factors of 42 : ±1 , ±2 , ±3 , ±6, ±7, ±14, ±21 , ±42
<u>Using trial and error method we will find the first root of the polynomial.</u>
1 : ( 1 )³ - 10 ( 1 )² - 53 ( 1 ) - 42
1 - 10 - 53 - 42 ≠ 0
Therefore 1 is not a root
-1 : ( -1 )³ - 10 (- 1 )² - 53 (- 1 ) - 42
- 1 - 10 + 53 - 42
53 - 53 = 0
Therefore - 1 is a root of the polynomial.
Therefore ( x + 1) is a factor.
<u>Now by long division or by using synthetic division we can find other factors.</u>
<u>Synthetic Division :</u>
-1 | 1 -10 -53 - 42
| 0 - 1 11 42
|______________________
1 - 11 - 42 0
Therefore ,
------ ( 1 )
<u>Next further factorize x² - 11x - 42</u>
x² - 11x - 42
= x² - 14x + 3x - 42
=x(x - 14) + 3 (x - 14)
=(x + 3 )(x - 14)
Therefore ,

5x-10+6 (then you sum the like terms)
5x-4
the answer is B 5x-4
26
Hope this was helpful !
Answer:
-24/5
Step-by-step explanation:
The solution to the problem is as follows:
cscx < 0 means 1/sinx < 0, or sinx < 0.
sinx = -3/5 because you're dealing with a 3-4-5 triangle, and we established
sinx is negative.
sin2x = 2sinxcosx = 2*-3/5*4/5 = -24/25
cos(2x) = cos^2(x) - sin^2(x) = 16/25 - 9/25 = 5/25 = 1/5
tan2x = sin2x / cos2x = -24/5