I am extremely confused. Any help?

(x-4)(5x³+18x²+54x+215)+860

Step-by-step explanation:

This follows that when the fourth degree polynomial is divided by the monomial(x-4),it gives a third degree polynomial and some remainder r

That is:

5x⁴-2x³-18x²-x/x-4=(ax³+bx²+cx+d)+r

if so,then

5x⁴-2x³-18x²-x=(x-4)(ax³+bx²+cx+d)+r

5x⁴-2x³-18x²-x=ax⁴+bx³+cx²+dx-4ax³-4bx²-4cx-4d+r

5x⁴-2x³-18x²-x=ax⁴+x³(b-4a)+x²(c-4b)+x(d-4c)-4d+r

We can now equate the similar terms thus,the terms with the same power of x on both sides

5x⁴=ax⁴,a=5

Again,

b-4a=-2,but a=5

b-4(5)=-2

b-20=-2

b=18

Again,

c-4b=-18(but b=18)

c-4(18)=-18

c-72=-18

c=54

Again,

d-4c=-1(but c=54)

d-4(54)=-1

d-216=-1

d=215

Finally,

-4d+r=0(but d=215)

-4(215)+r=0

r-860=0

r=860

This means that when 5x⁴-2x³-18x²-x is divided by x-4,it gives5x³+18x²+54x+215 with a remainder of 860

Now rewriting it in the form as required by the question=(x-4)(5x³+18x²+54x+215)+860