Write a polynomial equation of degree 4 that has the following roots : -1 repeated three times and 4

x^4 -x^3 -9x^2 -11x -4

Step-by-step explanation:

We can use the zero product property

(x-a)  (x-b) (x-c) (x-d)  where a b c d are the roots

(x- -1)(x- -1)(x- -1) ( x-4) since the root -1 is repeated 3 times and 4 is a root

(x+1)(x+1)(x+1) ( x-4)

Foil the first two terms  and the last two terms

(x^2 + 2x+1)( x^2 -3x-4)

Foil again

x^4 -3x^3 -4x^2 +2x^3 -6x^2 -8x +x^2 -3x-4

Combine like terms

x^4 -x^3 -9x^2 -11x -4

b) 1/3 * 1/5

step-by-step explanation:

each smallest part is 1/15 since the written one is 1/5 and it's divided by 3 equal parts. (1/5 )/3 = 1/15 = 1/3 * 1/5