(36x^3-60x^2-87x-21)divided by 9x+3

do long division

*******_4x^2__- 8x___-7_________________
(9x+3)/ 36x^3 - 60x^2 -87 x -21
********36x^3 + 12x^2
********-------------
************** -72x^2 -87 x -21
************** -72x^2 -24 x
***************----------------
********************* -63 x -21
********************* -63 x -21
remainder = 0
so 4x^2-8x-7