(3x+5) is a factor of the polynomial (a-1)x^3 + (a+1)x^2 - (2a + 1)x - 15. Find the value of 'a'. For this value of 'a', factorize the given expression completely.

(3x + 5)(x + √3)(x - √3)

a = 4

Step-by-step explanation:

(3x+5) is a factor of the polynomial (a-1)x³ + (a+1)x² - (2a + 1)x - 15

Means x = -5/3 is a root

(a-1)(-5/3)³ + (a+1)(-5/3)² - (2a + 1)(-5/3) - 15 = 0

-125a/27 + 125/27 + 25a/9 + 25/9 + 10a/3 + 5/3 - 15 = 0

a(-125/27 + 25/9 + 10/3) = 15 - 5/3 - 25/9 - 125/27

a(40/27) = 160/27

a = 4

x =±sqrt(1/3)

step-by-step explanation:

x+4/6x=1/x

multiply each side by 6x to get rid of the fractions

6x*(x+4/6x)=1/x*6x

distribute

6x^2 +4 = 6

subtract 4 from each side

6x^2 +4-4 = 6-4

6x^2 =2

divide by 6

6x^2/6 = 2/6

x^2 = 1/3

take the square root of each side

sqrt(x^2) = ±sqrt(1/3)

x =±sqrt(1/3)

7.25

step-by-step explanation:

we know that 7 equals to 7.0. we also know that 1/4=0.25. so we can add the two together and we get 7.25